US20080286976A1 - Method of removing a metal silicide layer on a gate electrode in a semiconductor manufacturing process and etching method - Google Patents
Method of removing a metal silicide layer on a gate electrode in a semiconductor manufacturing process and etching method Download PDFInfo
- Publication number
- US20080286976A1 US20080286976A1 US12/138,428 US13842808A US2008286976A1 US 20080286976 A1 US20080286976 A1 US 20080286976A1 US 13842808 A US13842808 A US 13842808A US 2008286976 A1 US2008286976 A1 US 2008286976A1
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- Prior art keywords
- layer
- gate electrode
- metal silicide
- metal
- etching
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- 229910052751 metal Inorganic materials 0.000 title claims abstract description 80
- 239000002184 metal Substances 0.000 title claims abstract description 80
- 238000000034 method Methods 0.000 title claims abstract description 69
- 229910021332 silicide Inorganic materials 0.000 title claims abstract description 48
- FVBUAEGBCNSCDD-UHFFFAOYSA-N silicide(4-) Chemical compound [Si-4] FVBUAEGBCNSCDD-UHFFFAOYSA-N 0.000 title claims abstract description 48
- 238000005530 etching Methods 0.000 title claims abstract description 34
- 239000004065 semiconductor Substances 0.000 title abstract description 22
- 238000004519 manufacturing process Methods 0.000 title abstract description 17
- 230000008569 process Effects 0.000 claims abstract description 42
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 claims description 16
- 238000001312 dry etching Methods 0.000 claims description 10
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 claims description 8
- KZBUYRJDOAKODT-UHFFFAOYSA-N Chlorine Chemical compound ClCl KZBUYRJDOAKODT-UHFFFAOYSA-N 0.000 claims description 8
- 229910052786 argon Inorganic materials 0.000 claims description 8
- 229910002091 carbon monoxide Inorganic materials 0.000 claims description 8
- RUFLMLWJRZAWLJ-UHFFFAOYSA-N nickel silicide Chemical compound [Ni]=[Si]=[Ni] RUFLMLWJRZAWLJ-UHFFFAOYSA-N 0.000 claims description 7
- 229910021334 nickel silicide Inorganic materials 0.000 claims description 7
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 5
- 229910017052 cobalt Inorganic materials 0.000 claims description 2
- 239000010941 cobalt Substances 0.000 claims description 2
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 claims description 2
- 229910052581 Si3N4 Inorganic materials 0.000 abstract description 28
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 abstract description 24
- 125000006850 spacer group Chemical group 0.000 abstract description 9
- 238000005498 polishing Methods 0.000 abstract description 6
- 239000000126 substance Substances 0.000 abstract description 4
- 238000007517 polishing process Methods 0.000 abstract description 2
- 206010010144 Completed suicide Diseases 0.000 abstract 1
- 239000010410 layer Substances 0.000 description 112
- 229910021420 polycrystalline silicon Inorganic materials 0.000 description 27
- 229920005591 polysilicon Polymers 0.000 description 27
- 239000000758 substrate Substances 0.000 description 14
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 12
- DNIAPMSPPWPWGF-UHFFFAOYSA-N Propylene glycol Chemical compound CC(O)CO DNIAPMSPPWPWGF-UHFFFAOYSA-N 0.000 description 12
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 12
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 9
- 229910052710 silicon Inorganic materials 0.000 description 9
- 239000010703 silicon Substances 0.000 description 9
- 241000027294 Fusi Species 0.000 description 7
- 150000004767 nitrides Chemical class 0.000 description 5
- 239000000377 silicon dioxide Substances 0.000 description 5
- 238000001039 wet etching Methods 0.000 description 5
- LDDQLRUQCUTJBB-UHFFFAOYSA-N ammonium fluoride Chemical compound [NH4+].[F-] LDDQLRUQCUTJBB-UHFFFAOYSA-N 0.000 description 4
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- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 2
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 2
- 229910004541 SiN Inorganic materials 0.000 description 2
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 description 2
- 229910052796 boron Inorganic materials 0.000 description 2
- 229910052681 coesite Inorganic materials 0.000 description 2
- 229910052906 cristobalite Inorganic materials 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 229910052759 nickel Inorganic materials 0.000 description 2
- PXHVJJICTQNCMI-UHFFFAOYSA-N nickel Substances [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- PEUPIGGLJVUNEU-UHFFFAOYSA-N nickel silicon Chemical compound [Si].[Ni] PEUPIGGLJVUNEU-UHFFFAOYSA-N 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- 238000000623 plasma-assisted chemical vapour deposition Methods 0.000 description 2
- 229910052814 silicon oxide Inorganic materials 0.000 description 2
- 238000004544 sputter deposition Methods 0.000 description 2
- 229910052682 stishovite Inorganic materials 0.000 description 2
- 229910052905 tridymite Inorganic materials 0.000 description 2
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 1
- 229910004160 TaO2 Inorganic materials 0.000 description 1
- QXZUUHYBWMWJHK-UHFFFAOYSA-N [Co].[Ni] Chemical compound [Co].[Ni] QXZUUHYBWMWJHK-UHFFFAOYSA-N 0.000 description 1
- 230000004913 activation Effects 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 1
- 238000000137 annealing Methods 0.000 description 1
- 229910052787 antimony Inorganic materials 0.000 description 1
- WATWJIUSRGPENY-UHFFFAOYSA-N antimony atom Chemical compound [Sb] WATWJIUSRGPENY-UHFFFAOYSA-N 0.000 description 1
- 229910052785 arsenic Inorganic materials 0.000 description 1
- RQNWIZPPADIBDY-UHFFFAOYSA-N arsenic atom Chemical compound [As] RQNWIZPPADIBDY-UHFFFAOYSA-N 0.000 description 1
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- 125000002915 carbonyl group Chemical group [*:2]C([*:1])=O 0.000 description 1
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- 238000005229 chemical vapour deposition Methods 0.000 description 1
- 239000000460 chlorine Substances 0.000 description 1
- 229910052801 chlorine Inorganic materials 0.000 description 1
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- 230000003247 decreasing effect Effects 0.000 description 1
- 239000003989 dielectric material Substances 0.000 description 1
- 239000003085 diluting agent Substances 0.000 description 1
- NQKXFODBPINZFK-UHFFFAOYSA-N dioxotantalum Chemical compound O=[Ta]=O NQKXFODBPINZFK-UHFFFAOYSA-N 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- CJNBYAVZURUTKZ-UHFFFAOYSA-N hafnium(IV) oxide Inorganic materials O=[Hf]=O CJNBYAVZURUTKZ-UHFFFAOYSA-N 0.000 description 1
- BHEPBYXIRTUNPN-UHFFFAOYSA-N hydridophosphorus(.) (triplet) Chemical compound [PH] BHEPBYXIRTUNPN-UHFFFAOYSA-N 0.000 description 1
- 239000012212 insulator Substances 0.000 description 1
- 239000011229 interlayer Substances 0.000 description 1
- 238000010849 ion bombardment Methods 0.000 description 1
- 238000005468 ion implantation Methods 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
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- 239000000047 product Substances 0.000 description 1
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L29/00—Semiconductor devices adapted for rectifying, amplifying, oscillating or switching, or capacitors or resistors with at least one potential-jump barrier or surface barrier, e.g. PN junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor
- H01L29/66—Types of semiconductor device ; Multistep manufacturing processes therefor
- H01L29/66007—Multistep manufacturing processes
- H01L29/66075—Multistep manufacturing processes of devices having semiconductor bodies comprising group 14 or group 13/15 materials
- H01L29/66227—Multistep manufacturing processes of devices having semiconductor bodies comprising group 14 or group 13/15 materials the devices being controllable only by the electric current supplied or the electric potential applied, to an electrode which does not carry the current to be rectified, amplified or switched, e.g. three-terminal devices
- H01L29/66409—Unipolar field-effect transistors
- H01L29/66477—Unipolar field-effect transistors with an insulated gate, i.e. MISFET
- H01L29/665—Unipolar field-effect transistors with an insulated gate, i.e. MISFET using self aligned silicidation, i.e. salicide
- H01L29/66507—Unipolar field-effect transistors with an insulated gate, i.e. MISFET using self aligned silicidation, i.e. salicide providing different silicide thicknesses on the gate and on source or drain
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer
- H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic System or AIIIBV compounds with or without impurities, e.g. doping materials
- H01L21/28—Manufacture of electrodes on semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/268
- H01L21/28008—Making conductor-insulator-semiconductor electrodes
- H01L21/28017—Making conductor-insulator-semiconductor electrodes the insulator being formed after the semiconductor body, the semiconductor being silicon
- H01L21/28026—Making conductor-insulator-semiconductor electrodes the insulator being formed after the semiconductor body, the semiconductor being silicon characterised by the conductor
- H01L21/28079—Making conductor-insulator-semiconductor electrodes the insulator being formed after the semiconductor body, the semiconductor being silicon characterised by the conductor the final conductor layer next to the insulator being a single metal, e.g. Ta, W, Mo, Al
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer
- H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic System or AIIIBV compounds with or without impurities, e.g. doping materials
- H01L21/28—Manufacture of electrodes on semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/268
- H01L21/28008—Making conductor-insulator-semiconductor electrodes
- H01L21/28017—Making conductor-insulator-semiconductor electrodes the insulator being formed after the semiconductor body, the semiconductor being silicon
- H01L21/28026—Making conductor-insulator-semiconductor electrodes the insulator being formed after the semiconductor body, the semiconductor being silicon characterised by the conductor
- H01L21/28088—Making conductor-insulator-semiconductor electrodes the insulator being formed after the semiconductor body, the semiconductor being silicon characterised by the conductor the final conductor layer next to the insulator being a composite, e.g. TiN
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer
- H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic System or AIIIBV compounds with or without impurities, e.g. doping materials
- H01L21/28—Manufacture of electrodes on semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/268
- H01L21/28008—Making conductor-insulator-semiconductor electrodes
- H01L21/28017—Making conductor-insulator-semiconductor electrodes the insulator being formed after the semiconductor body, the semiconductor being silicon
- H01L21/28026—Making conductor-insulator-semiconductor electrodes the insulator being formed after the semiconductor body, the semiconductor being silicon characterised by the conductor
- H01L21/28097—Making conductor-insulator-semiconductor electrodes the insulator being formed after the semiconductor body, the semiconductor being silicon characterised by the conductor the final conductor layer next to the insulator being a metallic silicide
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer
- H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic System or AIIIBV compounds with or without impurities, e.g. doping materials
- H01L21/30—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26
- H01L21/31—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26 to form insulating layers thereon, e.g. for masking or by using photolithographic techniques; After treatment of these layers; Selection of materials for these layers
- H01L21/3205—Deposition of non-insulating-, e.g. conductive- or resistive-, layers on insulating layers; After-treatment of these layers
- H01L21/321—After treatment
- H01L21/3213—Physical or chemical etching of the layers, e.g. to produce a patterned layer from a pre-deposited extensive layer
- H01L21/32133—Physical or chemical etching of the layers, e.g. to produce a patterned layer from a pre-deposited extensive layer by chemical means only
- H01L21/32134—Physical or chemical etching of the layers, e.g. to produce a patterned layer from a pre-deposited extensive layer by chemical means only by liquid etching only
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer
- H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic System or AIIIBV compounds with or without impurities, e.g. doping materials
- H01L21/30—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26
- H01L21/31—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26 to form insulating layers thereon, e.g. for masking or by using photolithographic techniques; After treatment of these layers; Selection of materials for these layers
- H01L21/3205—Deposition of non-insulating-, e.g. conductive- or resistive-, layers on insulating layers; After-treatment of these layers
- H01L21/321—After treatment
- H01L21/3213—Physical or chemical etching of the layers, e.g. to produce a patterned layer from a pre-deposited extensive layer
- H01L21/32133—Physical or chemical etching of the layers, e.g. to produce a patterned layer from a pre-deposited extensive layer by chemical means only
- H01L21/32135—Physical or chemical etching of the layers, e.g. to produce a patterned layer from a pre-deposited extensive layer by chemical means only by vapour etching only
- H01L21/32136—Physical or chemical etching of the layers, e.g. to produce a patterned layer from a pre-deposited extensive layer by chemical means only by vapour etching only using plasmas
- H01L21/32137—Physical or chemical etching of the layers, e.g. to produce a patterned layer from a pre-deposited extensive layer by chemical means only by vapour etching only using plasmas of silicon-containing layers
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L29/00—Semiconductor devices adapted for rectifying, amplifying, oscillating or switching, or capacitors or resistors with at least one potential-jump barrier or surface barrier, e.g. PN junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor
- H01L29/66—Types of semiconductor device ; Multistep manufacturing processes therefor
- H01L29/66007—Multistep manufacturing processes
- H01L29/66075—Multistep manufacturing processes of devices having semiconductor bodies comprising group 14 or group 13/15 materials
- H01L29/66227—Multistep manufacturing processes of devices having semiconductor bodies comprising group 14 or group 13/15 materials the devices being controllable only by the electric current supplied or the electric potential applied, to an electrode which does not carry the current to be rectified, amplified or switched, e.g. three-terminal devices
- H01L29/66409—Unipolar field-effect transistors
- H01L29/66477—Unipolar field-effect transistors with an insulated gate, i.e. MISFET
- H01L29/66545—Unipolar field-effect transistors with an insulated gate, i.e. MISFET using a dummy, i.e. replacement gate in a process wherein at least a part of the final gate is self aligned to the dummy gate
Definitions
- the present invention relate to a semiconductor device manufacturing process, and particularly to removal of a salicide layer in a semiconductor device manufacturing process.
- FIGS. 1 to 5 are cross-sectional views illustrating a MOS transistor 10 having a metal gate electrode fabricated according to a known process.
- a polysilicon gate electrode 12 is formed on a semiconductor substrate comprising a silicon layer 16 , and a shallow-junction source extension 17 and a shallow-junction drain extension 19 are formed in the silicon layer 16 at both sides of the polysilicon gate electrode 12 and separated by a channel region 22 .
- a spacer 32 is formed on both lateral walls of the polysilicon gate electrode 12 , and source and drain regions 18 and 20 are formed in the silicon layer 16 at both sides of the polysilicon gate electrode 12 and border the shallow-junction source extension 17 and the shallow-junction drain extension 19 .
- a gate dielectric layer 14 separates a gate electrode 12 from the channel region 22 .
- a liner 30 generally comprising silicon dioxide, is interposed between the gate electrode 12 and the silicon nitride spacer 32 .
- a metal silicide layer 42 is formed on the top of the polysilicon gate electrode 12 and the surface of the source and drain regions 18 and 20
- a silicon nitride cap layer 46 is formed on the entire area of the semiconductor substrate having the source and drain regions 18 and 20 and the shallow-junction source extension 17 and the shallow-junction drain extension 19 , so that the polysilicon gate electrode 12 can be covered.
- a dielectric layer 48 is formed on the nitride layer 46 .
- the silicon nitride cap layer 46 is usually between about 300 and about 1000 ⁇ (angstrom) in thickness, and is formed by a plasma enhanced chemical vapor deposition (PECVD) process.
- PECVD plasma enhanced chemical vapor deposition
- the nitride layer 42 and the dielectric layer 48 are polished by a CMP process until the top of the polysilicon gate electrode 12 is exposed.
- the CMP process is performed by over polishing so that the top of the polysilicon gate electrode 12 can be exposed completely.
- the remaining polysilicon gate electrode 12 is removed by a plasma reactive ion etch (RIE) using chlorine or a wet polysilicon etch using conventional etch chemistry to form an opening (i.e. recess) 54 .
- RIE plasma reactive ion etch
- a barrier metal layer 56 may be formed on the sidewall of the recess 54 and on the surface of the dielectric layer 48 , the nitride layer 46 , the spacers 32 , and the liner 30 , and then a metal layer 58 is deposited to fill the recess and on the barrier metal layer 56 .
- the surplus portion of metal layer 58 is polished away, forming a MOS transistor 10 having a metal gate.
- the fabrication method described above includes an integration flow of metal gate replacement process consisting of an ILD (inter-layer dielectric) CMP (chemical mechanical polishing) after a transistor being built, a removal of a metal silicide layer and a polysilicon plug, a metal layer deposition, and a metal CMP.
- ILD inter-layer dielectric
- CMP chemical mechanical polishing
- FUSI gates (fully silicided polysilicon gates) offer a potential metal gate alternative due to a relative simplicity of the integration process.
- the nitride layer 42 on the top of the gate electrode 1 2 and the dielectric layer 48 are polished by a CMP process until the top of the polysilicon gate electrode 12 is exposed.
- a metal layer 50 is deposited on the exposed region of the polysilicon gate electrode 12 , the nitride layer 46 , the spacers 32 , the liner 30 , and the dielectric layer 48 .
- the metal layer 50 is usually less than about 1000 ⁇ and, in some cases, may be between about 500 and about 1000 ⁇ in thickness.
- the metal layer 50 may be a multilayer of Ti/TiN, Co/TiN, or Co/Ti/TiN.
- a thermal treatment is performed on the substrate having the metal layer 50 to transform the polysilicon gate electrode into a metal silicide gate electrode 52 .
- the thermal treatment process may be performed through two steps, i.e., a first step at a temperature of about 400° C. to about 600° C., and a second step using a rapid thermal process (RTP) at a temperature of about 800° C. to about 1000° C. Subsequently, the residual metal layer, which has not reacted, is removed.
- the resultant MOS transistor 15 having a fully silicided gate electrode is shown in FIG. 7 .
- NiSi polycide is removed through a direct ILD CMP step and the full silicidaton of polysilicon is followed to form a NiSi metal gate.
- the difficulty to remove the metal silicide by a CMP process also exists in this method. It is very hard to control and polish the NiSi polycide layer with good removal uniformity directly using a CMP process.
- An object of the present invention is to provide a method of removing a metal silicide layer on a gate electrode in a semiconductor manufacturing process, to effectively and uniformly remove metal silicide layers on a gate electrode, such that the subsequently process can be performed advantageously.
- a wet etching method is also provided to effectively and uniformly remove metal silicide layers.
- a dry etching method is also provided to effectively and uniformly remove metal silicide layers.
- the gate electrode is disposed on a semiconductor substrate, the gate electrode has a top surface coated with a metal silicide layer, a spacer is disposed on each side wall formed by the gate electrode and the metal silicide layer together, a silicon nitride cap layer covers the metal silicide layer, the spacers, and the semiconductor substrate, and a dielectric layer covers the silicon nitride cap layer.
- the method of removing a metal silicide layer on a gate electrode in a semiconductor manufacturing process comprises steps of performing a chemical mechanical polishing process to polish the dielectric layer using the silicon nitride cap layer as a polishing stop layer to expose the silicon nitride cap layer over the gate electrode; removing the exposed silicon nitride cap layer to expose the metal silicide layer; and performing a first etching process to remove the metal silicide layer on the gate electrode.
- the wet etching method according to the present invention comprises a step of performing a wet etching process on a metal silicide layer using an etching solution.
- the etching solution comprises HF, NH 4 F, at least one selected from a group consisting of ethylene glycol and propylene glycol, and water.
- the dry etching method according to the present invention comprises a step of performing a dry etching process on a metal silicide layer using an etching recipe.
- the etching recipe comprises argon, at least one selected from a group consisting of hydrogen gas and chlorine gas, and carbon monoxide.
- the removal of metal silicide layers in the prior art is performed by means of a CMP process, and it is not easy to obtain a good polishing result.
- the method of the present invention has good etching selectivity, and thus an effective and a uniform removal of metal silicide layers on gate electrodes can be obtained to benefit the subsequent manufacturing process, therefore a semiconductor device with better quality can be obtained.
- FIGS. 1 to 5 are cross-sectional views illustrating a MOS transistor having a metal gate electrode fabricated according to a known process
- FIGS. 6 to 7 are cross-sectional views illustrating a MOS transistor having a FUSI gate electrode fabricated according to a known process
- FIGS. 8 to 17 are schematic cross-sectional diagrams illustrating a method of fabricating a semiconductor MOS transistor device having a metal gate in accordance with one preferred embodiment of the present invention.
- FIGS. 18 to 19 are schematic cross-sectional diagrams illustrating a method of fabricating a semiconductor MOS transistor device having a FUSI gate in accordance with one preferred embodiment of the present invention.
- the present invention pertains to a method of fabricating MOS transistor devices, such as NMOS, PMOS, and CMOS devices of integrated circuits, and especially to a removal method of a metal silicide layer on a gate electrode.
- FIGS. 8 to 17 are schematic cross-sectional diagrams illustrating a method of fabricating a semiconductor MOS transistor device 40 in accordance with one preferred embodiment of the present invention, wherein like number numerals designate similar or the same parts, regions or elements. It is to be understood that the drawings are not drawn to scale and are served only for illustration purposes.
- a semiconductor substrate generally comprising a silicon layer 16 is prepared.
- the semiconductor substrate may be a silicon substrate or a silicon-on-insulator (SOI) substrate, but is not limited thereto.
- An electrode such as a gate electrode 12 , is defined on the semiconductor substrate.
- a shallow-junction source extension 17 and a shallow-junction drain extension 19 may be formed in the silicon layer 16 .
- the source extension 17 and the drain extension 19 are separated by a channel 22 .
- a gate dielectric layer 14 may be formed to separate the gate electrode 12 from the channel 22 .
- the gate electrode 12 generally comprises polysilicon.
- the gate dielectric layer 14 may be a silicon dioxide film formed with thermal oxidation, or a silicon oxide/silicon nitride (ON) composite film formed with thermal oxidation and subsequent thermal nitridation.
- the gate dielectric layer 14 may be made of high-k materials known in the art, with a thickness between about 50 ⁇ and about 200 ⁇ , for example, formed by conventional methods of deposition, such as chemical vapor deposition.
- Typical materials that may be used in the high k gate dielectric layer 14 include ZrO 2 , HfO 2 , INO 2 , LaO 2 , and TaO 2 , for example.
- a silicon nitride spacer 32 is formed on sidewalls of the gate electrode 12 .
- a liner 30 such as silicon dioxide, may be interposed between the silicon nitride spacer 32 and the gate electrode 12 .
- the liners 30 are typically L shaped and have a thickness of about 30 to 120 ⁇ .
- the liner 30 may further comprise an offset spacer that is known in the art and is thus omitted in the drawings.
- a source region 18 and a drain region 20 may be further formed in the semiconductor substrate by an ion implantation process carried out by doping dopant species, such as N type dopant species (such as arsenic, antimony or phosphorous) for making an NMOS or P type dopant species (such as boron) for making a PMOS, into the silicon layer 16 .
- doping dopant species such as N type dopant species (such as arsenic, antimony or phosphorous) for making an NMOS or P type dopant species (such as boron) for making a PMOS.
- the substrate may be subjected to an annealing and/or activation thermal process that is known in the art.
- a layer such as a metal silicide layer 42 is formed on the gate electrode 12 , on the exposed source region 18 and on the exposed drain region 20 .
- the metal silicide layer 42 may be formed using the process known as self-aligned silicide (salicide) process, in which, after a source/drain region is formed, a metal layer is disposed on the source/drain region and the gate structure by a sputtering or plating, and a rapid thermal process (RTP) is performed to react the metal layer with the silicon contained within the gate structure and the source/drain region to form a metal silicide.
- silicide self-aligned silicide
- the metal silicide may be, for example, nickel silicon compound or nickel cobalt compound, such as, nickel silicide (NiSi) or cobalt silicide (CoSi 2 ).
- the temperature for RTP may be in the range of 700° C. to 1000° C. After the salicide layer is formed, the spacer 32 may be removed or retained as desired.
- a conformal silicon nitride cap layer 46 is further deposited on the substrate.
- the silicon nitride cap layer 46 covers the metal silicide layer 42 and the SiN spacer 32 and has a thickness of about 200 to 400 ⁇ .
- the silicon nitride cap layer 46 may function as a stop layer for an etching subsequently performed for making a contact hole.
- the silicon nitride cap layer 46 may be deposited in a compressive-stressed status to give the underlying source/drain region a strained structure for enhancement of electron or electric hole mobility of the channel region 22 .
- a dielectric layer 48 is deposited after the silicon nitride cap layer 46 is deposited.
- the dielectric layer 48 may comprise silicon oxide or high dielectric material, such as, multilayered metal oxide or perovskite.
- the dielectric layer 48 is typically much thicker than the silicon nitride cap layer 46 .
- the portion with a thickness A from top of dielectric layer 48 to the silicon nitride cap layer 46 over the gate electrode 12 is the portion to be removed using a CMP process in the method according to the present invention.
- FIG. 12 shows a resulting structure after a portion of the dielectric layer 48 shown in FIG, 11 is removed through the CMP process.
- the silicon nitride cap layer 46 may be used as a polishing stop layer, and then be removed by an etching.
- a hot phosphoric acid solution may be used as an etchant to etch away the exposed silicon nitride cap layer 46 .
- the silicon nitride cap layer 46 may be removed directly by CMP.
- FIG. 13 shows a resulting structure with an exposed metal silicide layer 42 on the gate after the silicon nitride cap layer 46 is removed.
- a wet etching may be performed using an etching solution comprising HF, NH 4 F, and at least one selected from a group consisting of ethylene glycol and propylene glycol in water.
- the weight ratio for HF:NH 4 F: the at least one selected from a group consisting of ethylene glycol and propylene glycol is preferably 0.5 to 6: 15 to 25:30 to 40.
- the etching solution includes about 3.5 weight % of HF, about 20 weight % of NH 4 F, about 35 weight % of ethylene glycol or propylene glycol, and the balanced water.
- the etching solution has an etching rate of 60.5 and 50.4 ⁇ /min respectively for NiSi and CoSi 2 , and 4.77, 6.01, and 1.4 ⁇ /min respectively for SiO 2 , polysilicon, and SiN, at 25° C. Therefore, the etching solution has a high selective ratio to effectively remove NiSi and CoSi 2 layers and the SiO 2 , polysilicon, and SiN structures remain. In the prior art, it is difficult to remove a NiSi or CoSi 2 layer by a CMP process.
- the metal silicide layer 42 on the gate electrode 12 may be also removed by a dry etching process.
- An etching gas may be used to perform the dry etching process on the metal silicide layer 42 on the gate electrode 12 .
- the etching recipe includes Ar, any one of H 2 and Cl 2 , and CO.
- CO reacts with the metal of the metal silicide to produce a volatile by-product having carbonyl groups, such as, Ni(CO) 4 .
- H 2 removes carbide film produced from chemical sputtering processes or formed from diluents for precursors of deposition. Ar ion bombardment may improve removal of products from etching.
- a flow rate ratio for argon: chlorine gas : carbon monoxide is preferably 5 to 15:15 to 25:5 to 15, or a flow rate ratio for argon : hydrogen gas : carbon monoxide is preferably 10 to 20:20 to 30:5 to 15.
- an etching recipe of CO, Cl 2 , and Ar is used.
- the flow rates of CO, Cl 2 , and Ar are respectively 100 sccm, 200 sccm, and 100 sccm.
- An etching tool, Model TCP9400 is used to perform the dry etching under a pressure of 10 mTorr at a temperature of 75° C. with a top power (TP) of 500 watts and a bottom power (BP) of 50 watts.
- TP top power
- BP bottom power
- an etching recipe of CO, H 2 , and Ar is used.
- the flow rates of CO, H 2 , and Ar are respectively 100 sccm, 250 sccm, and 150 sccm.
- An etching tool, Model DRM85, is used to perform the dry etching under a pressure of 30 mTorr at a temperature of 60° C. with a power of 1000 watts.
- the metal silicide layer 42 can be effectively removed in both embodiments.
- the metal silicide layer 42 mentioned above may be a metal silicide layer formed by a salicide process to a silicon layer or a polysilicon layer. After the metal silicide layer 42 is removed, a resulting structure is as shown in FIG. 14 . Subsequently, an opening 60 can be formed as shown in FIG. 15 using a conventional plasma reactive ion etching (RIE) or a polysilicon wet etching. A barrier metal layer 62 may be formed on the sidewalls of the opening 60 and the surface of the dielectric layer 48 , and a metal layer 64 is subsequently deposited to fill the opening 60 , as shown in FIG. 16 . Finally, the portion of the metal layer 64 on the dielectric layer 48 is removed, obtaining a MOS transistor 40 having a metal gate, as shown in FIG. 17 .
- RIE plasma reactive ion etching
- a structure as shown in FIG. 14 may be referred to.
- the metal silicide layer 42 has been removed using the etching method of the present invention and the polysilicon gate electrode 12 is exposed.
- a metal layer 66 with a thickness of about 500 to about 1000 ⁇ or less than 1000 ⁇ as a conventional thickness, may be deposited on the polysilicon gate electrode 12 and the silicon nitride cap layer 46 .
- the metal layer 66 may comprise Ni, Co, Ti, Ti/TiN, Co/TiN, Co/Ti/TiN, or the like, or a multi-layer thereof, for example.
- the resulting substrate is subjected to a thermal treatment to allow reaction of the polysilicon with the metal, forming a metal silicide.
- the unreacted metal is removed, and a MOS transistor 70 having a full metal polycide gate is obtained, as shown in FIG. 19 .
- the method according to the present invention in which a means of etching to remove the metal silicide layer on the polysilicon gate electrode is used, has a superior etching selectivity and thus has an excellent removing result, such that the metal gate process or FUSI gate process can be proceeded satisfactorily.
Abstract
A method of removing a metal suicide layer on a gate electrode in a semiconductor manufacturing process is disclosed, in which the gate electrode, a metal silicide layer, a spacer, a silicon nitride cap layer, and a dielectric layer have been formed. The method includes performing a chemical mechanical polishing process to polish the dielectric layer using the silicon nitride cap layer as a polishing stop layer to expose the silicon nitride cap layer over the gate electrode; removing the exposed silicon nitride cap layer to expose the metal silicide layer; and performing a first etching process to remove the metal silicide layer on the gate electrode.
Description
- This is a divisional application of U.S. patent application Ser. No. 11/163,849 filed on Nov. 1, 2005, and the contents of which are included herein entirely by reference.
- 1. Field of the Invention
- The present invention relate to a semiconductor device manufacturing process, and particularly to removal of a salicide layer in a semiconductor device manufacturing process.
- 2. Description of the Prior Art
- Semiconductor device geometries have dramatically decreased in size since such devices were first introduced several decades ago. Today's fabrication plants are producing devices having 0.35 μm, 90 nm, and even 65 nm feature sizes or smaller. As geometries shrink, semiconductor manufacturing methods often need to be improved.
- As MOS devices have been integrated at a rapid speed, an existing process using polysilicon as a gate electrode has caused many problems such as high gate resistance, depletion of polysilicon, and boron penetration into a channel area. A known process including a metal gate electrode/high-k gate dielectric layer has been proposed to eliminate the poly depletion effect and to offer an option of a lower thermal budget process.
-
FIGS. 1 to 5 are cross-sectional views illustrating aMOS transistor 10 having a metal gate electrode fabricated according to a known process. Referring toFIG. 1 , apolysilicon gate electrode 12 is formed on a semiconductor substrate comprising asilicon layer 16, and a shallow-junction source extension 17 and a shallow-junction drain extension 19 are formed in thesilicon layer 16 at both sides of thepolysilicon gate electrode 12 and separated by achannel region 22. Then, aspacer 32 is formed on both lateral walls of thepolysilicon gate electrode 12, and source anddrain regions silicon layer 16 at both sides of thepolysilicon gate electrode 12 and border the shallow-junction source extension 17 and the shallow-junction drain extension 19. A gatedielectric layer 14 separates agate electrode 12 from thechannel region 22. Aliner 30, generally comprising silicon dioxide, is interposed between thegate electrode 12 and thesilicon nitride spacer 32. Subsequently, ametal silicide layer 42 is formed on the top of thepolysilicon gate electrode 12 and the surface of the source anddrain regions nitride cap layer 46 is formed on the entire area of the semiconductor substrate having the source anddrain regions junction source extension 17 and the shallow-junction drain extension 19, so that thepolysilicon gate electrode 12 can be covered. Next, adielectric layer 48 is formed on thenitride layer 46. The siliconnitride cap layer 46 is usually between about 300 and about 1000 Å (angstrom) in thickness, and is formed by a plasma enhanced chemical vapor deposition (PECVD) process. - Next, referring to
FIG. 2 , thenitride layer 42 and thedielectric layer 48 are polished by a CMP process until the top of thepolysilicon gate electrode 12 is exposed. The CMP process is performed by over polishing so that the top of thepolysilicon gate electrode 12 can be exposed completely. - Subsequently, referring to
FIG. 3 , the remainingpolysilicon gate electrode 12 is removed by a plasma reactive ion etch (RIE) using chlorine or a wet polysilicon etch using conventional etch chemistry to form an opening (i.e. recess) 54. Referring toFIG. 4 , abarrier metal layer 56 may be formed on the sidewall of therecess 54 and on the surface of thedielectric layer 48, thenitride layer 46, thespacers 32, and theliner 30, and then ametal layer 58 is deposited to fill the recess and on thebarrier metal layer 56. Finally, referring toFIG. 5 , the surplus portion ofmetal layer 58 is polished away, forming aMOS transistor 10 having a metal gate. - The fabrication method described above includes an integration flow of metal gate replacement process consisting of an ILD (inter-layer dielectric) CMP (chemical mechanical polishing) after a transistor being built, a removal of a metal silicide layer and a polysilicon plug, a metal layer deposition, and a metal CMP. However, it is very difficult to remove the metal silicide by a CMP process.
- FUSI gates (fully silicided polysilicon gates) offer a potential metal gate alternative due to a relative simplicity of the integration process. Referring to
FIG. 2 , thenitride layer 42 on the top of the gate electrode 1 2 and thedielectric layer 48 are polished by a CMP process until the top of thepolysilicon gate electrode 12 is exposed. Then, referring toFIG. 6 , ametal layer 50 is deposited on the exposed region of thepolysilicon gate electrode 12, thenitride layer 46, thespacers 32, theliner 30, and thedielectric layer 48. Themetal layer 50 is usually less than about 1000 Å and, in some cases, may be between about 500 and about 1000 Å in thickness. Themetal layer 50 may be a multilayer of Ti/TiN, Co/TiN, or Co/Ti/TiN. - A thermal treatment is performed on the substrate having the
metal layer 50 to transform the polysilicon gate electrode into a metalsilicide gate electrode 52. The thermal treatment process may be performed through two steps, i.e., a first step at a temperature of about 400° C. to about 600° C., and a second step using a rapid thermal process (RTP) at a temperature of about 800° C. to about 1000° C. Subsequently, the residual metal layer, which has not reacted, is removed. Theresultant MOS transistor 15 having a fully silicided gate electrode is shown inFIG. 7 . - In the fabrication method including a FUSI metal gate integration process described above, NiSi polycide is removed through a direct ILD CMP step and the full silicidaton of polysilicon is followed to form a NiSi metal gate. However, the difficulty to remove the metal silicide by a CMP process also exists in this method. It is very hard to control and polish the NiSi polycide layer with good removal uniformity directly using a CMP process.
- Therefore, there is still a need for a better method to remove a salicide layer in a semiconductor device manufacturing process.
- An object of the present invention is to provide a method of removing a metal silicide layer on a gate electrode in a semiconductor manufacturing process, to effectively and uniformly remove metal silicide layers on a gate electrode, such that the subsequently process can be performed advantageously.
- In an aspect of one embodiment according to the present invention, a wet etching method is also provided to effectively and uniformly remove metal silicide layers.
- In an aspect of another embodiment according to the present invention, a dry etching method is also provided to effectively and uniformly remove metal silicide layers.
- In the method of removing a metal silicide layer on a gate electrode in a semiconductor manufacturing process according to the present invention, the gate electrode is disposed on a semiconductor substrate, the gate electrode has a top surface coated with a metal silicide layer, a spacer is disposed on each side wall formed by the gate electrode and the metal silicide layer together, a silicon nitride cap layer covers the metal silicide layer, the spacers, and the semiconductor substrate, and a dielectric layer covers the silicon nitride cap layer. The method of removing a metal silicide layer on a gate electrode in a semiconductor manufacturing process comprises steps of performing a chemical mechanical polishing process to polish the dielectric layer using the silicon nitride cap layer as a polishing stop layer to expose the silicon nitride cap layer over the gate electrode; removing the exposed silicon nitride cap layer to expose the metal silicide layer; and performing a first etching process to remove the metal silicide layer on the gate electrode.
- The wet etching method according to the present invention comprises a step of performing a wet etching process on a metal silicide layer using an etching solution. The etching solution comprises HF, NH4F, at least one selected from a group consisting of ethylene glycol and propylene glycol, and water.
- The dry etching method according to the present invention comprises a step of performing a dry etching process on a metal silicide layer using an etching recipe. The etching recipe comprises argon, at least one selected from a group consisting of hydrogen gas and chlorine gas, and carbon monoxide.
- The removal of metal silicide layers in the prior art is performed by means of a CMP process, and it is not easy to obtain a good polishing result. Contrarily, the method of the present invention has good etching selectivity, and thus an effective and a uniform removal of metal silicide layers on gate electrodes can be obtained to benefit the subsequent manufacturing process, therefore a semiconductor device with better quality can be obtained.
- These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.
-
FIGS. 1 to 5 are cross-sectional views illustrating a MOS transistor having a metal gate electrode fabricated according to a known process; -
FIGS. 6 to 7 are cross-sectional views illustrating a MOS transistor having a FUSI gate electrode fabricated according to a known process; -
FIGS. 8 to 17 are schematic cross-sectional diagrams illustrating a method of fabricating a semiconductor MOS transistor device having a metal gate in accordance with one preferred embodiment of the present invention; and -
FIGS. 18 to 19 are schematic cross-sectional diagrams illustrating a method of fabricating a semiconductor MOS transistor device having a FUSI gate in accordance with one preferred embodiment of the present invention. - The present invention pertains to a method of fabricating MOS transistor devices, such as NMOS, PMOS, and CMOS devices of integrated circuits, and especially to a removal method of a metal silicide layer on a gate electrode.
- Please refer to
FIGS. 8 to 17 .FIGS. 8 to 17 are schematic cross-sectional diagrams illustrating a method of fabricating a semiconductorMOS transistor device 40 in accordance with one preferred embodiment of the present invention, wherein like number numerals designate similar or the same parts, regions or elements. It is to be understood that the drawings are not drawn to scale and are served only for illustration purposes. - As shown in
FIG. 8 , a semiconductor substrate generally comprising asilicon layer 16 is prepared. According to this invention, the semiconductor substrate may be a silicon substrate or a silicon-on-insulator (SOI) substrate, but is not limited thereto. An electrode, such as agate electrode 12, is defined on the semiconductor substrate. A shallow-junction source extension 17 and a shallow-junction drain extension 19 may be formed in thesilicon layer 16. Thesource extension 17 and thedrain extension 19 are separated by achannel 22. - A
gate dielectric layer 14 may be formed to separate thegate electrode 12 from thechannel 22. Thegate electrode 12 generally comprises polysilicon. Thegate dielectric layer 14 may be a silicon dioxide film formed with thermal oxidation, or a silicon oxide/silicon nitride (ON) composite film formed with thermal oxidation and subsequent thermal nitridation. However, in another case, thegate dielectric layer 14 may be made of high-k materials known in the art, with a thickness between about 50 Å and about 200 Å, for example, formed by conventional methods of deposition, such as chemical vapor deposition. Typical materials that may be used in the high kgate dielectric layer 14 include ZrO2, HfO2, INO2, LaO2, and TaO2, for example. Subsequently, asilicon nitride spacer 32 is formed on sidewalls of thegate electrode 12. Aliner 30, such as silicon dioxide, may be interposed between thesilicon nitride spacer 32 and thegate electrode 12. Theliners 30 are typically L shaped and have a thickness of about 30 to 120 Å. Theliner 30 may further comprise an offset spacer that is known in the art and is thus omitted in the drawings. - As shown in
FIG. 9 , after forming thesilicon nitride spacer 32, asource region 18 and adrain region 20 may be further formed in the semiconductor substrate by an ion implantation process carried out by doping dopant species, such as N type dopant species (such as arsenic, antimony or phosphorous) for making an NMOS or P type dopant species (such as boron) for making a PMOS, into thesilicon layer 16. After the source/drain doping, the substrate may be subjected to an annealing and/or activation thermal process that is known in the art. - As shown in
FIG. 10 , a layer, such as ametal silicide layer 42, is formed on thegate electrode 12, on the exposedsource region 18 and on the exposeddrain region 20. Themetal silicide layer 42 may be formed using the process known as self-aligned silicide (salicide) process, in which, after a source/drain region is formed, a metal layer is disposed on the source/drain region and the gate structure by a sputtering or plating, and a rapid thermal process (RTP) is performed to react the metal layer with the silicon contained within the gate structure and the source/drain region to form a metal silicide. The metal silicide may be, for example, nickel silicon compound or nickel cobalt compound, such as, nickel silicide (NiSi) or cobalt silicide (CoSi2). The temperature for RTP may be in the range of 700° C. to 1000° C. After the salicide layer is formed, thespacer 32 may be removed or retained as desired. - Subsequently, as shown in
FIG. 11 , a conformal siliconnitride cap layer 46 is further deposited on the substrate. The siliconnitride cap layer 46 covers themetal silicide layer 42 and theSiN spacer 32 and has a thickness of about 200 to 400 Å. The siliconnitride cap layer 46 may function as a stop layer for an etching subsequently performed for making a contact hole. The siliconnitride cap layer 46 may be deposited in a compressive-stressed status to give the underlying source/drain region a strained structure for enhancement of electron or electric hole mobility of thechannel region 22. Adielectric layer 48 is deposited after the siliconnitride cap layer 46 is deposited. Thedielectric layer 48 may comprise silicon oxide or high dielectric material, such as, multilayered metal oxide or perovskite. Thedielectric layer 48 is typically much thicker than the siliconnitride cap layer 46. The portion with a thickness A from top ofdielectric layer 48 to the siliconnitride cap layer 46 over thegate electrode 12 is the portion to be removed using a CMP process in the method according to the present invention. -
FIG. 12 shows a resulting structure after a portion of thedielectric layer 48 shown in FIG, 11 is removed through the CMP process. The siliconnitride cap layer 46 may be used as a polishing stop layer, and then be removed by an etching. A hot phosphoric acid solution may be used as an etchant to etch away the exposed siliconnitride cap layer 46. Alternatively, the siliconnitride cap layer 46 may be removed directly by CMP.FIG. 13 shows a resulting structure with an exposedmetal silicide layer 42 on the gate after the siliconnitride cap layer 46 is removed. - Subsequently, the
metal silicide layer 42 on thegate electrode 12 is removed by etching. A wet etching may be performed using an etching solution comprising HF, NH4F, and at least one selected from a group consisting of ethylene glycol and propylene glycol in water. In the etching solution, the weight ratio for HF:NH4F: the at least one selected from a group consisting of ethylene glycol and propylene glycol is preferably 0.5 to 6: 15 to 25:30 to 40. In one embodiment according to the present invention, the etching solution includes about 3.5 weight % of HF, about 20 weight % of NH4F, about 35 weight % of ethylene glycol or propylene glycol, and the balanced water. The etching solution has an etching rate of 60.5 and 50.4 Å/min respectively for NiSi and CoSi2, and 4.77, 6.01, and 1.4 Å/min respectively for SiO2, polysilicon, and SiN, at 25° C. Therefore, the etching solution has a high selective ratio to effectively remove NiSi and CoSi2 layers and the SiO2, polysilicon, and SiN structures remain. In the prior art, it is difficult to remove a NiSi or CoSi2 layer by a CMP process. - The
metal silicide layer 42 on thegate electrode 12 may be also removed by a dry etching process. An etching gas may be used to perform the dry etching process on themetal silicide layer 42 on thegate electrode 12. The etching recipe includes Ar, any one of H2 and Cl2, and CO. In the dry etching process, it is presumed that CO reacts with the metal of the metal silicide to produce a volatile by-product having carbonyl groups, such as, Ni(CO)4. H2 removes carbide film produced from chemical sputtering processes or formed from diluents for precursors of deposition. Ar ion bombardment may improve removal of products from etching. In the etching recipe, a flow rate ratio for argon: chlorine gas : carbon monoxide is preferably 5 to 15:15 to 25:5 to 15, or a flow rate ratio for argon : hydrogen gas : carbon monoxide is preferably 10 to 20:20 to 30:5 to 15. - In another embodiment according to the present invention, an etching recipe of CO, Cl2, and Ar is used. The flow rates of CO, Cl2, and Ar are respectively 100 sccm, 200 sccm, and 100 sccm. An etching tool, Model TCP9400, is used to perform the dry etching under a pressure of 10 mTorr at a temperature of 75° C. with a top power (TP) of 500 watts and a bottom power (BP) of 50 watts. In still another embodiment according to the present invention, an etching recipe of CO, H2, and Ar is used. The flow rates of CO, H2, and Ar are respectively 100 sccm, 250 sccm, and 150 sccm. An etching tool, Model DRM85, is used to perform the dry etching under a pressure of 30 mTorr at a temperature of 60° C. with a power of 1000 watts. The
metal silicide layer 42 can be effectively removed in both embodiments. - The
metal silicide layer 42 mentioned above may be a metal silicide layer formed by a salicide process to a silicon layer or a polysilicon layer. After themetal silicide layer 42 is removed, a resulting structure is as shown inFIG. 14 . Subsequently, anopening 60 can be formed as shown inFIG. 15 using a conventional plasma reactive ion etching (RIE) or a polysilicon wet etching. Abarrier metal layer 62 may be formed on the sidewalls of theopening 60 and the surface of thedielectric layer 48, and ametal layer 64 is subsequently deposited to fill theopening 60, as shown inFIG. 16 . Finally, the portion of themetal layer 64 on thedielectric layer 48 is removed, obtaining aMOS transistor 40 having a metal gate, as shown inFIG. 17 . - In case that a FUSI gate is desired to be manufactured, a structure as shown in
FIG. 14 may be referred to. In this structure, themetal silicide layer 42 has been removed using the etching method of the present invention and thepolysilicon gate electrode 12 is exposed. Next, please further refer toFIG. 18 , ametal layer 66, with a thickness of about 500 to about 1000 Å or less than 1000 Å as a conventional thickness, may be deposited on thepolysilicon gate electrode 12 and the siliconnitride cap layer 46. Themetal layer 66 may comprise Ni, Co, Ti, Ti/TiN, Co/TiN, Co/Ti/TiN, or the like, or a multi-layer thereof, for example. The resulting substrate is subjected to a thermal treatment to allow reaction of the polysilicon with the metal, forming a metal silicide. The unreacted metal is removed, and aMOS transistor 70 having a full metal polycide gate is obtained, as shown inFIG. 19 . - As compared with the conventional metal gate process or FUSI gate process using a CMP process to remove metal silicide layers on original gates, the method according to the present invention, in which a means of etching to remove the metal silicide layer on the polysilicon gate electrode is used, has a superior etching selectivity and thus has an excellent removing result, such that the metal gate process or FUSI gate process can be proceeded satisfactorily.
- Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.
Claims (6)
1. A dry etching method, comprising:
performing a dry etching process on a metal silicide layer using an etching recipe, wherein the etching recipe comprises argon, carbon monoxide, and at least one selected from the group consisting of hydrogen gas and chlorine gas.
2. The method of claim 1 , wherein in the etching recipe, a flow rate ratio for argon: hydrogen gas: carbon monoxide is 10 to 20:20 to 30:5 to 15.
3. The method of claim 2 , wherein in the etching recipe, a flow rate ratio for argon: hydrogen gas: carbon monoxide is 15:25:10.
4. The method of claim 1 , wherein in the etching recipe, a flow rate ratio for argon: chlorine gas: carbon monoxide is 5 to 15:15 to 25:5 to 15.
5. The method of claim 4 , wherein in the etching recipe, a flow rate ratio for argon: chlorine gas: carbon monoxide is 10:20:10.
6. The method of claim 1 , wherein the metal silicide layer comprises at least one selected from the group consisting of nickel silicide and cobalt silicide.
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US8274777B2 (en) | 2008-04-08 | 2012-09-25 | Micron Technology, Inc. | High aspect ratio openings |
US7759193B2 (en) * | 2008-07-09 | 2010-07-20 | Micron Technology, Inc. | Methods of forming a plurality of capacitors |
US8518788B2 (en) | 2010-08-11 | 2013-08-27 | Micron Technology, Inc. | Methods of forming a plurality of capacitors |
US20120309155A1 (en) * | 2011-06-03 | 2012-12-06 | Nanya Technology Corporation | Semiconductor process |
US9076680B2 (en) | 2011-10-18 | 2015-07-07 | Micron Technology, Inc. | Integrated circuitry, methods of forming capacitors, and methods of forming integrated circuitry comprising an array of capacitors and circuitry peripheral to the array |
CN103137458B (en) * | 2011-12-05 | 2016-03-30 | 中芯国际集成电路制造(上海)有限公司 | The manufacture method of high dielectric layer metal gate |
US8946043B2 (en) | 2011-12-21 | 2015-02-03 | Micron Technology, Inc. | Methods of forming capacitors |
US8652926B1 (en) | 2012-07-26 | 2014-02-18 | Micron Technology, Inc. | Methods of forming capacitors |
US10265742B2 (en) | 2013-11-25 | 2019-04-23 | Applied Materials, Inc. | Method for in-situ chamber clean using carbon monoxide (CO) gas utlized in an etch processing chamber |
CN105405751B (en) * | 2014-06-10 | 2018-07-20 | 中芯国际集成电路制造(上海)有限公司 | A kind of semiconductor devices and its manufacturing method, electronic device |
CN105575901B (en) * | 2014-10-14 | 2019-07-16 | 中芯国际集成电路制造(上海)有限公司 | The production method and semiconductor devices of semiconductor devices |
KR102342847B1 (en) | 2015-04-17 | 2021-12-23 | 삼성전자주식회사 | Semiconductor device and manufacturing method of the same |
Citations (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4569722A (en) * | 1984-11-23 | 1986-02-11 | At&T Bell Laboratories | Ethylene glycol etch for processes using metal silicides |
US5162259A (en) * | 1991-02-04 | 1992-11-10 | Motorola, Inc. | Method for forming a buried contact in a semiconductor device |
US5259923A (en) * | 1991-05-29 | 1993-11-09 | Tokyo Electron Limited | Dry etching method |
US5487811A (en) * | 1990-08-23 | 1996-01-30 | Fujitsu Limited | Process for preparation of semiconductor device |
US5994234A (en) * | 1996-12-12 | 1999-11-30 | Nec Corporation | Method for dry-etching a polycide film |
US6037265A (en) * | 1998-02-12 | 2000-03-14 | Applied Materials, Inc. | Etchant gas and a method for etching transistor gates |
US6146542A (en) * | 1998-01-09 | 2000-11-14 | Hyundia Electronics Industries Co., Ltd. | Dry etching method of multilayer film |
US20020025673A1 (en) * | 1999-12-17 | 2002-02-28 | Song Woon Young | Method for forming gate by using Co-silicide |
US6444584B1 (en) * | 1998-07-16 | 2002-09-03 | Taiwan Semiconductor Manufacturing Company | Plasma etch method for forming composite silicon/dielectric/silicon stack layer |
US6455428B1 (en) * | 2000-10-26 | 2002-09-24 | Vanguard International Semiconductor Corporation | Method of forming a metal silicide layer |
US6548344B1 (en) * | 2001-11-16 | 2003-04-15 | Infineon Technologies Ag | Spacer formation process using oxide shield |
US20040115952A1 (en) * | 2002-12-05 | 2004-06-17 | Samsung Electronics Co., Inc. | Cleaning solution and method for selectively removing layer in a silicidation process |
US20050054193A1 (en) * | 2003-09-09 | 2005-03-10 | Tien-Sung Chen | [interconnect process and method for removing metal silicide] |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
TW569347B (en) | 2002-10-03 | 2004-01-01 | Taiwan Semiconductor Mfg | Method for selectively removing metal compound dielectric layer with high dielectric constant |
JP2004273556A (en) | 2003-03-05 | 2004-09-30 | Matsushita Electric Ind Co Ltd | Semiconductor device and its manufacturing method |
-
2005
- 2005-11-01 US US11/163,849 patent/US7544621B2/en active Active
-
2008
- 2008-06-13 US US12/138,428 patent/US20080286976A1/en not_active Abandoned
Patent Citations (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4569722A (en) * | 1984-11-23 | 1986-02-11 | At&T Bell Laboratories | Ethylene glycol etch for processes using metal silicides |
US5487811A (en) * | 1990-08-23 | 1996-01-30 | Fujitsu Limited | Process for preparation of semiconductor device |
US5162259A (en) * | 1991-02-04 | 1992-11-10 | Motorola, Inc. | Method for forming a buried contact in a semiconductor device |
US5259923A (en) * | 1991-05-29 | 1993-11-09 | Tokyo Electron Limited | Dry etching method |
US5994234A (en) * | 1996-12-12 | 1999-11-30 | Nec Corporation | Method for dry-etching a polycide film |
US6146542A (en) * | 1998-01-09 | 2000-11-14 | Hyundia Electronics Industries Co., Ltd. | Dry etching method of multilayer film |
US6037265A (en) * | 1998-02-12 | 2000-03-14 | Applied Materials, Inc. | Etchant gas and a method for etching transistor gates |
US6444584B1 (en) * | 1998-07-16 | 2002-09-03 | Taiwan Semiconductor Manufacturing Company | Plasma etch method for forming composite silicon/dielectric/silicon stack layer |
US20020025673A1 (en) * | 1999-12-17 | 2002-02-28 | Song Woon Young | Method for forming gate by using Co-silicide |
US6455428B1 (en) * | 2000-10-26 | 2002-09-24 | Vanguard International Semiconductor Corporation | Method of forming a metal silicide layer |
US6548344B1 (en) * | 2001-11-16 | 2003-04-15 | Infineon Technologies Ag | Spacer formation process using oxide shield |
US20040115952A1 (en) * | 2002-12-05 | 2004-06-17 | Samsung Electronics Co., Inc. | Cleaning solution and method for selectively removing layer in a silicidation process |
US20050054193A1 (en) * | 2003-09-09 | 2005-03-10 | Tien-Sung Chen | [interconnect process and method for removing metal silicide] |
US6881670B2 (en) * | 2003-09-09 | 2005-04-19 | Nanya Technology Corporation | Interconnect process and method for removing metal silicide |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20120244716A1 (en) * | 2011-03-22 | 2012-09-27 | Tokyo Electron Limited | Substrate processing method and storage medium |
US8715520B2 (en) * | 2011-03-22 | 2014-05-06 | Tokyo Electron Limited | Substrate processing method and storage medium |
KR101924796B1 (en) * | 2011-03-22 | 2018-12-04 | 도쿄엘렉트론가부시키가이샤 | Substrate processing method and storage medium |
US10392175B2 (en) | 2014-02-21 | 2019-08-27 | Lf Centennial Ltd. | Waterproof container |
Also Published As
Publication number | Publication date |
---|---|
US20070099423A1 (en) | 2007-05-03 |
US7544621B2 (en) | 2009-06-09 |
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