CN1893001B

CN1893001B - Method for manufacturing semiconductor device

Info

Publication number: CN1893001B
Application number: CN2006100997260A
Authority: CN
Inventors: 张宏勇; 高山彻; 竹村保彦
Original assignee: Semiconductor Energy Laboratory Co Ltd
Current assignee: Semiconductor Energy Laboratory Co Ltd
Priority date: 1993-03-12
Filing date: 1994-03-12
Publication date: 2011-10-05
Anticipated expiration: 2014-03-12
Also published as: CN1893118B; CN1893001A; JP3137797B2; CN1893118A; CN1893000A; CN1893000B; JPH06267978A

Abstract

A method for fabricating a semiconductor device is characterized in that the method comprises the following steps: forming a crystal semiconductor film on a substrate having a insulating layer; forming a gate insulating film including silicon dioxide by utilizing tetraethoxysilane on the crystal semiconductor film; forming a gate electrode adjacent to the crystal semiconductor film, wherein a gate insulating film is inserted between the crystal semiconductor film and the gate electrode, and the gate electrode includes a kind of material selected from a group of material of tantalum, titanium, tungsten, molybdenum, silicon; and introducing impurity element to the crystal semiconductor film by the gate insulating film so as to form at least a impurity zone on the crystal semiconductor film.

Description

The manufacture method of semiconductor device

The application is dividing an application of application number is 2004100351663, the applying date is on March 12nd, 1994 original bill application, and the first of this original bill is JP93-78997 in first to file, and the first applying date formerly is on March 12nd, 1993.

Technical field

The present invention relates to a kind of thin-film transistor (TFT) and manufacture method thereof.Can be made on the dielectric substrate such as glass according to thin-film transistor of the present invention, also can be made in as on the substrate of making by crystalline silicon.Particularly the present invention relates to a kind of thin-film transistor of making by processing steps such as crystallization and thermal annealing activation.

Background technology

Recently, the insulated-gate semiconductor device that comprises a dielectric substrate and be provided with a film active layer (also being referred to as active area sometimes) has thereon been carried out research effectively.Particularly, be that great effort has been paid in the research of usually said thin-film transistor (TFT) to the film-type gated transistor.A plurality of TFT are made on the transparent dielectric substrate, mainly are in order to come gating matrix to drive each pixel or the drive circuit of display unit with them.Semi-conductive material and the state used according to TFT can be divided into TFT non-crystalline silicon tft and silicon metal TFT.

In above-mentioned many TFT, the manufacturing of amorphous TFT can stand the high-temperature technology process.Amorphous TFT drops into practicality already, because when they being manufactured on the large tracts of land substrate, and its rate of finished products height.General inverted ladder type (also the being referred to as bottom gate type) non-crystalline silicon tft that in the non-crystalline silicon tft of reality, adopts.The gate electrode of this type of non-crystalline silicon tft is located at the below of active area.

The processing step of making existing TFT comprises: form a gate electrode on a substrate; Formation is as the amorphous silicon film and the active layer of gate insulating film; And on amorphous silicon film, form the fine and closely woven silicon fiml of a N type crystallization, so that source and drain region to be set.Yet, owing to the corrosion rate of N type silicon fiml and the amorphous silicon film that is provided with as substrate much at one, so the extra step of this technological requirement for example is provided with a corrosion stop layer and similar layer.

As a kind of measure that overcomes the problems referred to above, a kind of ion doping technology that is used for is provided, high-speed ion directly is injected into the method in formation source and leakage in the amorphous silicon film.

But this method still has unsatisfactory part, because the crystallinity of the ion implanted region that it produces is obviously damaged.The conductivity in these districts is low, thereby still is unsuitable for practicality.Also once propose, with laser beam and similarly luminous energy these districts are annealed, increasing its crystallinity, yet this method is not suitable for batch process.

Present actual useful method is the method that makes recrystallized amorphous siliconization by heating.But this method requires the annealing 600 ℃ or above temperature.Thereby owing to this technology of problem of substrate also is out of favour.More particularly, the alkali-free glass substrate that generally is used for non-crystalline silicon tft promptly begins distortion (as Corning#7059 glass substrate softening point at 593 ℃) under 600 ℃ or lower temperature.600 ℃ annealing glass substrate is shunk or distortion.

And 600 ℃ annealing can damage the characteristic of the previous amorphous silicon of making at low temperatures.More particularly, make active area also stand crystallization at 600 ℃, and completely lost favourable characteristic, promptly non-crystalline silicon tft no longer has the feature of its low-leakage current.This problem requires crystallization process more carrying out (preferably in 50 ℃ of deformation temperatures that is lower than glass or lower again temperature) under the low temperature.

Generally, be in amorphous semiconductor and have low electric field mobility.Thereby they can not be used for the TFT of requirement working at high speed.And the electric field mobility of P type amorphous silicon is extremely low.This just makes the manufacturing of P ditch TFT (PMOS TFT) unworkable.Infer the MOS circuit that can not get complementation with this, because for realizing that CMOS must combine with N ditch TFT (NMOS TFT) by P ditch TFT.

Compare with amorphous semiconductor, crystalline semiconductor has higher electric field mobility, thereby is applicable to the TFT of working at high speed.Being also advantageous in that of silicon metal made cmos circuit easily with it, because can not only obtain NMOS TFT by silicon metal, and can also obtain PMOS TFT.Therefore a kind of LCD with the driven with active matrix that is called single chip architecture is proposed, not only in the active matrix part, and at the crystal TFT composition of peripheral circuit (for example drive circuit) by CMOS.Owing to these reasons, make to research and the exploitation of the TFT that uses silicon metal more active recently.

Can obtain silicon metal to amorphous silicon with the high light irradiation that laser or light intensity equate.Yet this technology is unsuitable for producing in batches; And unstable, because laser output itself is just unstable, also because technical process is too short.

A kind of practicable technology that makes recrystallized amorphous siliconization is to adopt heat treatment, i.e. thermal crystallization recently.This technology can be produced the uniform silicon metal of quality, no matter in batches how.But this technology still has problems, and waits to solve.

Generally, thermal crystallization requires to implement annealing for a long time at about 600 ℃, or up to 1000 ℃ of temperature, or even higher annealing temperature.The back is planted the feasible selection to backing material of technology and is narrowed down, because it can not be applied to the substrate except that quartz substrate, aforesaid processing also has other problems.

Specifically, the technical process of using cheap alkali-free glass substrate (as the Corning#7059 glass substrate) to make TFT comprises:

Deposit one deck amorphous silicon film on substrate;

600 ℃ or higher temperature through 24 hours or chien shih amorphous silicon film crystallization when longer;

Deposit one deck gate insulating film;

Form gate electrode;

Introduce impurity (injecting or ion doping) with ion;

Make the impurity activation of mixing 600 ℃ or higher temperature through 24 hours or longer time annealing;

Form interlevel insulator; And

Formation source and drain region.

In above-mentioned processing step, find that the 6th step was a problem the impurity activation of mixing most.(softening temperature as Corning#7059 glass is 593 ℃) can distortion near 600 ℃ for most of alkali-free glasss.This just means, must consider the contraction of substrate in this step.In second step, i.e. annealing steps, the contraction of substrate is unchallenged, because also do not constitute figure on substrate.Yet in the 6th step, forming circuit figure on substrate if substrate shrinks, can not carry out mask alignment in several steps of back.This obviously can reduce rate of finished products.This just requires to carry out for the 6th step at a lower temperature, is preferably in than carrying out under glass deformation temperature low 50 ℃ or lower again the temperature.

As previously mentioned, use laser can reduce technological temperature.But the poor reliability of this technology because laser instability not only, but also owing to by the position of laser irradiation (source and drain region) with not by the different stress that produce of temperature rise between the position of laser irradiation (active area is the zone of gate electrode below).

Summary of the invention

Thereby use laser to make TFT to be difficult, not find as yet that at present other effective measures overcome these problems.The present invention provides a kind of solution for above-mentioned difficulties.The purpose that is the present invention is to propose a kind of technology that overcomes the problems referred to above and be suitable for producing in batches.

As the result of present inventors' broad research, the crystallization that discovery is essentially the silicon fiml of amorphous can be accelerated by adding micro-catalysis material.According to said method, crystallization can be finished in the short time in lower temperature.Preferred catalysis material comprises some simple metal promptly: nickel (Ni), iron (Fe), cobalt (Co) and platinum (Pt), or a kind of compound, and as the silicide of element cited herein.Specifically, technology according to the present invention comprises: on the amorphous silicon film or under and with it contact form a kind of material that contains the catalytic elements of shapes such as film, particle, agglomerate, and in a suitable temperature, generally at 580 ℃ or low again, be preferably in 550 ℃ or lowlyer again the material thermal annealings of formation are made it crystallization.Another kind method is, needn't form a kind of material that catalytic elements contacts with amorphous silicon film that contains, and replaces to use such as methods such as ion injections catalytic elements is mixed amorphous silicon film.

Certainly, improve the cycle that the temperature of annealing can shorten crystallization.And, along with the increase of nickel, iron, cobalt or platinum concentration shortened in the cycle of crystallization, the temperature step-down of crystallization.By deep research, present inventors find, at least a above-mentioned catalytic elements mix concentration 1 * 10 ¹⁷Cm ^-3More than can quicken crystallization, its concentration is preferably in 5 * 10 ¹⁸Cm ^-3Or it is higher.

But above-listed each catalysis material is unfavorable to silicon.Thereby, preferably its concentration is controlled to alap level.By research, present inventors find that the preferable range of total concentration is 1 * 10 ²⁰Cm ^-3Or it is low again.Particularly, at active layer, the concentration of catalysis material must control to 1 * 10 ¹⁸Cm ^-3Or below, be preferably lower than 1 * 10 ¹⁷Cm ^-3, be lower than 1 * 10 ¹⁶Cm ^-3Then better.

Description of drawings

Fig. 1 (A)-1 (E) schematically illustrates the resulting sequenced section of structure of technology by one embodiment of the invention (embodiment 1);

Fig. 2 (A)-2 (E) schematically illustrates the resulting sequenced section of structure of technology by another embodiment of the present invention (embodiment 2);

Fig. 3 (A)-3 (E) schematically illustrate by the technology of another embodiment of the present invention (embodiment 3) the sequenced section of structure that arrived; And

Fig. 4 (A)-4 (E) schematically illustrates the resulting sequenced section of structure of technology by another embodiment of the present invention (embodiment 4).

Embodiment

As previously mentioned, present inventors have noticed the effect of catalytic elements, and find to utilize these yuan usually to overcome problem in the prior art technology.A kind of technology according to embodiment making TFT of the present invention comprises:

Form a gate electrode;

Deposit one gate insulating film;

Deposit one deck amorphous silicon film;

With ion injection or ion doping impurity is introduced in the amorphous silicon film;

On this silicon fiml, form the material film that contains a kind of catalytic elements;

In heat treatment below 500 ℃ or 550 ℃ no longer than making the impurity activation of mixing in 8 hours; And

Formation source and drain electrode.

A kind of technology by another embodiment of the present invention comprises:

Form a gate electrode;

Deposit one deck gate insulating film;

Deposit one deck amorphous silicon film;

With ion injection or ion doping impurity is introduced amorphous silicon film;

With ion injection or ion doping catalytic elements is introduced this silicon fiml;

At 550 ℃ or be lower than 550 ℃ of heat treatments no longer than making the impurity activation of mixing in 8 hours; And

Formation source and drain electrode.

In above-mentioned processing step, the order in the 4th step and a step thereafter is interconvertible.That is, the doping step both can also can carried out thereafter before introducing the catalytic elements step.It mainly is the crystallization that the catalytic elements in introducing source and drain region has been quickened this two district significantly.Therefore be enough to finish activation 550 ℃ or following temperature, generally carry out 500 ℃ or lower again temperature.Annealing 8 hours or shorter, generally is annealing 4 hours or shorter enough.Particularly, find that crystallization carries out extremely rapidly when with ion injection or ion doping catalytic elements being introduced silicon fiml, because find that element is to be evenly distributed in the silicon fiml.

In doping impurity, can use mask that catalytic elements is mixed in the silicon fiml.Press self-aligned manner, shine behind from gate electrode and can obtain this mask.

Another kind of technology of making TFT by another embodiment of the present invention comprises:

Deposit one deck amorphous silicon film;

Amorphous silicon film 600 ℃ or the heating of temperature more than it 24 hours or longer, is made its crystallization;

Deposit one deck gate insulating film;

Form a gate electrode;

With ion injection or ion doping impurity is introduced amorphous silicon film;

Deposit one deck contains a kind of film of catalytic elements on silicon fiml;

600 ℃ or its following heat treatment no longer than making the impurity activation of mixing in 8 hours;

Form interlevel insulator; And

Formation source and drain electrode.

Another technology of making TFT by an embodiment of the present invention comprises:

Deposit one deck amorphous silicon film;

600 ℃ or more than it with amorphous silicon film heating 24 hours or longer, make its crystallization;

Deposit one deck gate insulating film;

Form a gate electrode;

With ion injection or ion doping impurity is introduced amorphous silicon film;

With ion injection or ion doping a kind of catalytic elements is introduced this silicon fiml;

Form interlevel insulator; And

Formation source and drain electrode.

In above-mentioned processing step, the 5th step and its, next step order can be put upside down.That is doping step, both can also can carried out thereafter before introducing the catalytic elements step.It mainly is the crystallization that the catalytic elements in introducing source and drain region has been quickened this two district significantly.Thereby, at 600 ℃ or be enough to below it activate, generally at 550 ℃ or below it.For annealing, 8 hours or short, generally with 4 hours or shorter enough.Particularly, when catalytic elements being introduced silicon fiml, find that crystallization carries out extremely rapidly, because find that element is evenly distributed in the silicon fiml with ion injection or ion doping.

Being characterised in that of technology of the present invention, this technology comprise, add the disadvantageous catalytic elements of silicon, but are forced into extremely low-level 1 * 10 in the concentration of active area ¹⁸Cm ^-3Or below it.That is, all aforementioned technologies include, and provide a mask or gate electrode for active area when mixing.Thereby catalytic elements can directly not touch or inject into active area.And keep reliability and the characteristic of TFT not weakened.Particularly, with Ni mix its concentration of impurity range be 10 times of active area or more than, set annealing temperature and time more according to qualifications, impurity range is activated and keeps amorphous state simultaneously.Because annealing is finished, can not run into the temperature difference that occurs in the laser annealing under heat balance.

Below with reference to infinite embodiment, the present invention is done more detailed description.But should be appreciated that this non-limitation of the present invention.

Embodiment 1

Fig. 1 represents by the resulting section of structure by the step preface of the technology of one embodiment of the invention.With reference to Fig. 1, forming a layer thickness on Corning#7059 glass substrate 1 is 3000-8000

Tantalum film, and constitute figure, form gate electrode 2.Then, with tantalum film surface anodic oxidation, formation thickness is 1000-3000

For example 2000

Anode oxide film 3.Be 1000-5000 with plasma CVD deposit one layer thickness then For example 1500 Silicon nitride film 4.And then be 200-1500 with plasma CVD deposit thereon one layer thickness For example 500 Intrinsic (I-type) amorphous silicon film.The amorphous silicon film composition that obtains is at last obtained semiconductor regions 5, shown in Fig. 1 (A).

With resultant substrate surface by coated with photoresist, and from the substrate back exposure, to form the mask 6 consistent, shown in Fig. 1 (B) with gate electrode figure.

Use ion doping, use resulting mask 6, phosphorus is injected semiconductor region 5 as impurity.With hydrogen phosphide (PH ₃) carrying out ion doping as impurity gas, used accelerating voltage is at 60-90KV, 80KV for example, used dosage is 1 * 10 ¹⁵-8 * 10 ¹⁵Cm ^-2Scope.In the case, the dosage that mixes of phosphorus is 2 * 10 ¹⁵Cm ^-2Form N type impurity range 7a and 7b with the method, shown in Fig. 1 (C).

Then, with mask 6 by ion doping inject nickel from.Used dosage is 2 * 10 ¹³-2 * 10 ¹⁴Cm ^-2, more particularly for example be 5 * 10 ¹³Cm ^-2Its result finds the concentration about 5 * 10 of nickel in N

type impurity range

26a and 26b ¹⁸Cm ^-3So just obtained the structure shown in strength 1 (D).

Then, with resulting structures in containing the nitrogen atmosphere that partial pressure is preferably the atmospheric hydrogen of 0.1-1 500 ℃ of annealing 4 hours.With the method activator impurity.Because nickel ion is injected into impurity range in advance, because nickel, finds that the crystallization in these zones has been accelerated to the catalytic action of crystallization.Impurity range 7a and 7b have so just been activated.

Use plasma CVD deposit 3000 subsequently

Thick silicon oxide film 8 as interlevel insulator, forms contact hole thereon with more source and the drain region of TFT, with the multilayer film of metal-containing material such as titanium nitride and aluminium, sets up the electrode of band interconnection 9a and 9b.This has just finished a complete thin-film transistor, shown in Fig. 1 (E).

Measure the impurity range of the TFT that makes by above-mentioned technology and the nickel concentration of active area with ion microprobe (SIMS).Recording impurity range, to contain nickel concentration be 1 * 10 ¹⁸-5 * 10 ¹⁸Cm ^-3This detects the limit 1 * 10 with being lower than ¹⁶Cm ^-3The concentration of active area form tangible contrast.

Embodiment 2

Fig. 2 represents with the resulting profile that respectively goes on foot the preface structure of an embodiment of the present invention.With reference to Fig. 2, forming thickness on Corning#7059 glass substrate 11 is 3000-8000

For example 5000

Tantalum film, and composition forms gate electrode 12.Then, use anode oxidation method, making the surface formation thickness of tantalum film is 1000-3000

For example 2000

Anode oxide film.Then, be 1000-5000 with the plasma CVD method deposition thickness For example be 1500

Silicon nitride film 14.And then, be 200-1500 with the plasma CVD deposition thickness thereon For example be 500 in this example Intrinsic (I type) amorphous silicon film.With the amorphous silicon film composition that obtains to obtain semiconductor region 15, shown in Fig. 2 (A).

Lining one deck photoresist on the surface of gained substrate, from the back-exposure of substrate to form and the consistent mask 16 of gate electrode figure shown in Fig. 2 (B).

By the ion doping method,, make impurity with phosphorus and inject semiconductor region 15 with the mask 16 of gained.With hydrogen phosphide (PH ₃) finish ion doping as impurity gas, added accelerating voltage is for example used 80KV at 60-90KV, and dosage is 1 * 10 ¹⁵-8 * 10 ¹⁵Cm ^-2Mixing the used dosage of phosphorus in this example is 2 * 10 ¹⁵Cm ^-2In this way, N type impurity range 17a and 17b have been formed, shown in Fig. 2 (C).

Then, be 5-200 with sputtering method deposition thickness on whole surface

For example 20 One deck nickel silicide film (be expressed as NiSi with chemical formula _x, X is 0.4-2.5 for example 2.0 herein) and 18.Because resulting film is as thin as about 20

, it seems as some, and unlike continuous film.The outward appearance of film is so unimportant in this example.So just obtained the structure shown in Fig. 2 (D).

Then, resulting structures is annealed in hydrogeneous atmosphere, used temperature is 450 ℃, and 4 hours time, the partial pressure of hydrogen is preferably the 0.1-1 atmospheric pressure.In this way, activator impurity.Because nickel silicide film 18 is deposits in advance,, the crystallization of N type impurity range 17a and 17b is played catalyst action by its diffusion nickle atom.So just quickened the crystallization in these districts, impurity range 17a and 17b are activated.

Subsequently, with plasma CVD deposit one deck 3000 Thick silicon oxide film 19 is as interlevel insulator, and forms contact hole thereon, so that be source and the drain region of TFT, with the multilayer film of metal-containing material such as titanium nitride and aluminium, sets up the electrode of band interconnection 20a and 20b.This has just finished a complete thin-film transistor, shown in Fig. 2 (E).

Measure the impurity range of the TFT that makes by above-mentioned technology and the concentration of active area nickel with ion microprobe (SIMS).Recording impurity range, to contain nickel concentration be 1 * 10 ¹⁸-3 * 10 ¹⁸This with 1 * 10 ¹⁶-5 * 10 ¹⁶The active area concentration of scope becomes distinct contrast.

Embodiment 3

Fig. 3 represents with the prepared profile that respectively goes on foot the preface structure of the technology of another embodiment of the present invention.With reference to Fig. 3, on a Corning#7059 glass substrate 110, form one deck 2000 with sputtering method Thick silicon oxide film 111 is as counterdie.Then, with plasma CVD thereon deposition thickness be 500-1500 , for example 1500 Intrinsic (I type) amorphous silicon film.Then, in blanket of nitrogen, annealed 48 hours for 600 ℃, make the amorphous silicon film crystallization.After the annealing, silicon fiml is constituted figure form island silicon area 112, with sputtering method deposit one deck 1000 thereon

Thick silicon oxide film 113 is as gate insulating film.Sputtering technology is to carry out with the target of silica as sputter in the atmosphere that contains oxygen and argon, and argon is not higher than 0.5 to the ratio of oxygen, for example is below 0.1 or 0.1.In technical process, substrate temperature remains on 200-400 ℃, for example 350 ℃.

Then, be 6000-8000 with decompression CVD deposition thickness For example 6000 Phosphorous be the silicon fiml of 0.1-2%.The step of silicon oxide deposition film step best and the deposit silicon fiml is carried out continuously.The silicon fiml composition of gained is formed gate electrode 114, shown in Fig. 3 (A).

Then, use plasma doping, make mask, phosphorus is introduced silicon area as impurity with gate electrode.With hydrogen phosphide (PH ₃) as impurity gas, mix, used accelerating voltage is 60-90KV, for example is 80KV, used dosage is 1 * 10 ¹⁵-8 * 10 ¹⁵Cm ^-2The phosphorus dosage that is mixed in the present embodiment is 2 * 10 ¹⁵Cm ^-2In this way, N

type impurity range

115a and 115b have been formed, shown in Fig. 3 (B).

The silicon oxide film 113 of corrosion on the impurity range to be exposing impurity range 115, is 5-200 with the sputtering method deposition thickness on whole surface

, for example 20 Nickel silicide film (use chemical formula NiSi _xExpression, X is 0.4-2.5 herein, for example 2.0) 116.Because the film of gained is approximately 20

Thin, it seems as granule, unlike continuous film.In this example, the outward appearance of this film is so unimportant.So just obtained the structure shown in Fig. 3 (C).

Then, resulting structures is put into blanket of nitrogen and anneal 4 hours with activator impurity at 500 ℃.Because nickel diffuses into N

type impurity range

115a and 115b from the nickel silicide film thereon of deposit in advance, find to have quickened the generation of crystallization through annealing.In this way,

impurity range

115a and 115b have been activated.Resulting structures is shown in Fig. 3 (D).

Then, with plasma CVD deposit 6000

Thick silicon oxide film 117 is as interlayer insulating film, leaving the contact hole metal-containing material thereon, is the source of TFT and the electrode that the drain region

forms band interconnection

118a and 118b as the multilayer film of titanium nitride and aluminium.At last, resulting structures was annealed 30 minutes at 350 ℃ in 1 atmospheric nitrogen atmosphere.So just finished a complete thin-film transistor, shown in Fig. 3 (E).

Measure the source of the TFT that makes by above-mentioned technology and the concentration of drain region and active area nickel with ion microprobe (SIMS).The nickel concentration that contains in discovery source and drain region is 1 * 10 ¹⁸-5 * 10 ¹⁸Cm ^-3This detects the limit 1 * 10 with being lower than ¹⁶Cm ^-3The concentration of active area become striking contrast.

Embodiment 4

Fig. 4 represents with the prepared agent face figure that respectively goes on foot the preface structure of the technology of another embodiment of the present invention.With reference to Fig. 4, on a Corning#7059 glass substrate 29, form one deck 2000 with sputtering method Thick silicon oxide film is made counterdie.Then, with plasma CVD deposit one deck intrinsic (I type) amorphous silicon film thereon, its thickness is at 500-1500 Scope, for example 1500

Then, in blanket of nitrogen,, make the amorphous silicon film crystallization 600 ℃ of annealing 48 hours.After the annealing, the silicon fiml composition is formed island silicon fiml 22.

Then, use plasma CVD, use tetrem oxosilane (TEOS, Si (OC ₂H ₅) ₄) and oxygen as raw material deposit one deck 1000 The silicon oxide film of depositing 23 is as gate insulating film.So in the original gas material, add trichloroethylene.Before thin film deposition began, to the logical oxygen of reaction chamber, when total pressure is remained on 5Pa, underlayer temperature was 300 ℃ with the flow of 400SCCM (per minute standard cubic centimeter), and when applying the RF power of 150W, produced plasma in reaction chamber.This state kept 10 minutes.Then, to be respectively 300SCCM, the flow of 15SCCM and 2SCCM feeds oxygen, TEOS and trichloroethylene to reaction chamber, the silicon oxide deposition film.During deposition film, make underlayer temperature, RF power and total pressure remain on 300 ℃, 75W and 5Pa respectively.When finishing thin film deposition, feeding pressure to reaction chamber is the hydrogen of 100Torr, to finish 350 ℃ hydrogen annealing 35 minutes.

Subsequently, use the sputtering method deposition thickness at 3000-8000 , for example be 6000

Tantalum film.Can use titanium, tungsten, molybdenum or silicon to replace tantalum.Yet this film must have sufficiently high heat resistance, handles with the activation of withstanding afterwards.Two step depositing steps of silicon oxide film 23 and tantalum film preferably carry out continuously.The tantalum film composition is formed the gate electrode 24 of TFT.With tantalum film surface anodic oxidation, form oxide layer 25 in its surface again.Anodic oxidation is to carry out in the ethylene glycol solution of the Tartaric acid that contains 1-5%.So obtain 2000

Thick oxide layer is as Fig. 4 (A).

As the mask plasma doping, phosphorus is injected silicon area as impurity with gate electrode.With hydrogen phosphide (PH ₃) carry out doping process as impurity gas, used accelerating voltage 80KV.In this example, with 2 * 10 ¹⁵Cm ^-2Dosage mix phosphorus.In this way, N

type impurity range

26a and 26b have been formed.Can see that the impurity range of setting up in this situation 26 has departed from gate electrode 24, shown in Fig. 4 (B).

Then, make mask with ion doping with gate electrode and inject nickel ion.Introduce the used dosage of nickel 2 * 10 ¹³-2 * 10 ¹⁴Cm ^-2Scope, for example more specifically use 5 * 10 ¹³Cm ^-2Its result finds that the concentration of nickel in N type impurity range 26a6 and 26b is approximately 5 * 10 ¹⁸Cm ^-3So obtain the structure shown in Fig. 4 (C).

Then the structure of gained was annealed 4 hours at 500 ℃ in blanket of nitrogen, with activator impurity.Because nickel ion is injected into N

type impurity range

26a and 26b in advance, find because nickel to the catalytic action of crystallization, has quickened the carrying out that recrystallizes in these

zones.So impurity range

26a and 26b are activated.Resulting structures is shown in Fig. 4 (D).

Subsequently, make raw material, with plasma CVD deposit 2000 with TEOS

Thick silicon oxide film 27 forms contact hole thereon as interlevel insulator, is the source of TFT and the electrode that the drain region forms band

interconnection

28a and 28b with the multilayer film of metal-containing material such as titanium nitride and aluminium.So finished complete semiconductor circuit, shown in Fig. 4 (E).

Find the thin-film transistor of making like this, when gate voltage was 10V, its field-effect mobility was at 70-100cm ²/ Vs scope, when apply to grid-during 20V voltage, its threshold voltage is 2.5-4.0V, leakage current is 10 ¹³A or lower.

The present invention with the impurity activation of mixing, has improved the output of thin-film transistor by in during 4 hours weak point under 500 ℃ low temperature.Thereby the invention provides a kind of method that solves the prior art problem, because in 600 ℃ or the high-temperature technology that carried out more than it, run into the serious like this problem of glass substrate distortion, realized that under above-mentioned low like this temperature crystallization avoided glass substrate to shrink and crooked.

Above-named advantage of the present invention also comprises can the large-area substrate of single treatment.More particularly, be cut into a plurality of semiconductor circuits (as matrix circuit) by the large tracts of land substrate.Thereby can reduce the single cost of circuit significantly.When being applied to the production of LCD, can boost productivity and improve the performance of display according to technology of the present invention.As seen by above-mentioned, the present invention can be widely used in industrial production.

Although at length narrated the present invention with reference to specific embodiment, those skilled in the art should understand, does not break away from spirit of the present invention and category and can carry out variation miscellaneous and remodeling.

Claims

1. method of making semiconductor device may further comprise the steps:

On insulating surface, form one deck amorphous silicon film;

Make the amorphous silicon film crystallization so that form crystal silicon film;

Use tetraethoxysilane and oxygen on described crystal silicon film, to form one deck silicon oxide film;

The hydrogen annealing silicon oxide film;

Form gate electrode on described silicon oxide film, described gate electrode comprises a kind of material of selecting at least from the group that tantalum, titanium, tungsten, molybdenum and silicon constitute;

Passing described silicon oxide film introduces a kind of impurity form two impurity ranges in described crystal silicon film;

With concentration at 1x10 ¹⁷Cm ^-3Above catalytic elements is introduced two impurity ranges;

On described gate electrode, form one deck dielectric film;

A contact hole of described dielectric film and described silicon oxide film is passed in formation; And

The multilayer film that utilization comprises metal material is the electrode that the band interconnection of described contact hole is passed in a formation in two impurity ranges.

2. according to the process of claim 1 wherein that described impurity is phosphorus.

3. according to the process of claim 1 wherein that described silicon oxide film forms by plasma CVD.

4. method of making semiconductor device may further comprise the steps:

On insulating surface, form one deck amorphous silicon film;

Use tetraethoxysilane, oxygen and trichloroethylene on described crystal silicon film, to form one deck silicon oxide film;

The hydrogen annealing silicon oxide film;

On described gate electrode, form one deck dielectric film;

5. according to the method for claim 4, wherein said impurity is phosphorus.

6. according to the method for claim 4, wherein said silicon oxide film forms by plasma CVD.

7. method of making semiconductor device may further comprise the steps:

On insulating surface, form one deck amorphous silicon film;

The hydrogen annealing silicon oxide film;

Use tetraethoxysilane on described gate electrode, to form one deck dielectric film;

8. according to the method for claim 7, wherein said impurity is phosphorus.

9. according to the method for claim 7, wherein said silicon oxide film forms by plasma CVD.

10. method of making semiconductor device may further comprise the steps:

On insulating surface, form one deck amorphous silicon film;

The hydrogen annealing silicon oxide film;

The described impurity range of annealing is used for the activation of described impurity in a nitrogen atmosphere;

On described gate electrode, form one deck dielectric film;

11. according to the method for claim 10, wherein said impurity is phosphorus.

12. according to the method for claim 10, wherein said silicon oxide film forms by plasma CVD.

13. a method of making semiconductor device may further comprise the steps:

On substrate, form one deck first silicon oxide film,

On described first silicon oxide film, form one deck amorphous silicon film;

Use tetraethoxysilane and oxygen on described crystal silicon film, to form one deck second silicon oxide film;

Hydrogen annealing second silicon oxide film;

Form gate electrode on described second silicon oxide film, described gate electrode comprises a kind of material of selecting at least from the group that tantalum, titanium, tungsten, molybdenum and silicon constitute;

Passing described second silicon oxide film introduces a kind of impurity form two impurity ranges in described crystal silicon film;

On described gate electrode, form one deck dielectric film;

A contact hole of described dielectric film and described second silicon oxide film is passed in formation; And

14. according to the method for claim 13, wherein said impurity is phosphorus.

15. according to the method for claim 13, wherein said second silicon oxide film forms by plasma CVD.