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(12) United States Patent
Hoist et al.
(io) Patent No.: US 6,833,024 B2 (45) Date of Patent: Dec. 21,2004
(54) ABATEMENT OF EFFLUENT FROM CHEMICAL VAPOR DEPOSITION PROCESSES USING LIGAND EXCHANGE RESISTANT METAL-ORGANIC PRECURSOR SOLUTIONS
(75) Inventors: Mark Hoist, Sunnyvale, CA (US);
Rebecca Faller, Hayward, CA (US);
Glenn Tom, New Milford, CT (US);
Jose Arno, Brookfield, CT (US); Ray
Dubois, Gilbert, AZ (US)
(73) Assignee: Adanced Technology Materials, Inc.,
D anbury, CT (US)
( * ) Notice: Subject to any disclaimer, the term of this patent is extended or adjusted under 35 U.S.C. 154(b) by 76 days.
(21) Appl. No.: 10/278,276
(22) Filed: Oct. 23, 2002
(65) Prior Publication Data
US 2003/0056726 Al Mar. 27, 2003
Related U.S. Application Data
(62) Division of application No. 09/420,107, filed on Oct. 18, 1999, now Pat. No. 6,500,487.
(51) Int. CI.7 B01D 53/04; C23C 16/00
(52) U.S. CI 96/108; 96/109; 96/111;
96/134; 96/142; 96/143; 423/210; 423/230;
423/250; 73/23.2; 118/715
(58) Field of Search 118/715; 96/108,
96/109, 111, 126, 34, 142-146; 423/210, 220, 230, 226, 236, 234.1; 73/24.01, 23.2,
(56) References Cited
U.S. PATENT DOCUMENTS
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4,842,746 A 6/1989 Fowler et al.
5,114,683 A 5/1992 Hirase 422/173
5,151,110 A 9/1992 Bein et al 55/75
5,151,395 A 9/1992 Tom 502/67
5,187,131 A 2/1993 Tigglebeck et al 502/34
5,356,849 A 10/1994 Matviya et al 502/180
5,417,934 A 5/1995 Smith et al 422/177
5,443,623 A * 8/1995 Jonas et al 95/101
5,444,249 A 8/1995 Wong
5,445,008 A 8/1995 Wachter et al 73/24.06
5,494,869 A 2/1996 Hayden et al 502/22
5,648,114 A 7/1997 Paz De Araujo
(List continued on next page.)
B. Zorich & M. Majors, "Safety and Environmental Concerns of CVD Copper Precursors" Solid State Tech. Sep. 1998, pp. 101-106.
Laura Mendicine, Paul Thomas Brown, "The Environment, Health and Safety Side of Copper Metalization," Semiconductor Inter., Jun. 1998, pp. 105-110.
Primary Examiner—Jeffrie R. Lund
(74) Attorney, Agent, or Firm—Margaret Chappuis; Marianne Fuierer; Tristan Anne Fuierer
Apparatus and method for abatement of effluent from multicomponent metal oxides deposited by CVD processes using metal source reagent liquid solutions which comprise at least one metal coordination complex including a metal to which is coordinatively bound at least one ligand in a stable complex and a suitable solvent medium for that metal coordination complex e.g., a metalorganic chemical vapor deposition (MOCVD) process for forming barium strontium titanate (BST) thin films on substrates. The effluent is sorptively treated to remove precursor species and MOCVD process by-products from the effluent. An endpoint detector such as a quartz microbalance detector may be employed to detect incipient breakthrough conditions in the sorptive treatment unit.
13 Claims, 1 Drawing Sheet
5,820,664 A 10/1998 Gardiner et al 106/287.17
5,827,947 A 10/1998 Miller et al 73/24.06
5,928,426 A * 7/1999 Aitchison 118/715
6,030,591 A * 2/2000 Tom et al 423/240 S
6,090,208 A * 7/2000 Han 118/715
6,099,649 A 8/2000 Schmitt et al 118/715
6,110,531 A 8/2000 Paz de Araujo
6,238,514 Bl * 5/2001 Gu 156/345.29
6,279,503 Bl * 8/2001 Choi et al 118/715
6,328,804 Bl * 12/2001 Murzin et al 427/255.28
6,383,300 Bl * 5/2002 Saito et al 118/715
6,391,385 Bl * 5/2002 Hoist et al 427/250
6,500,487 Bl * 12/2002 Hoist et al 427/248.1
6,537,353 B2 * 3/2003 Hoist et al 96/108
6,749,671 B2 * 6/2004 Hoist et al 96/108
2002/0094380 Al * 7/2002 Hoist et al 118/715
2003/0056726 Al * 3/2003 Hoist et al 118/715
2003/0136265 Al * 7/2003 Hoist et al 96/108
ABATEMENT OF EFFLUENT FROM CHEMICAL VAPOR DEPOSITION PROCESSES USING LIGAND EXCHANGE RESISTANT METAL-ORGANIC PRECURSOR SOLUTIONS
This is a division of U.S. application Ser. No. 09/420, 107. File date Oct. 18, 1999 now U.S. Pat. No. 6,500,487.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method and apparatus for abatement of effluent from any CVD process using a metal source reagent liquid solution comprising at least one metal coordination complex including a metal to which is coordinatively bound at least one ligand in a stable complex and a solvent for that metal coordination complex e.g., abatement of effluent from a multi-component metal oxide chemical vapor deposition (CVD) process used for forming barium strontium titanate (BST) thin films on substrates.
2. Description of the Related Art
BST is an important material in the semiconductor manufacturing industry for fabrication of thin film dielectric microelectronic devices. Such fabrication typically is carried out by chemical vapor deposition (CVD), in which precursors (source reagents) for the respective barium, strontium and titanium components of the product film are volatilized for use in the deposition process.
The source reagents for the BST film formation process may be provided to the CVD reactor by a liquid delivery process, in which the metalorganic precursors for the barium, strontium and titanium components are dissolved in a suitable solvent medium such as n-butyl acetate or tetrahydrofuran. The liquid solution containing precursors and corresponding solvent (separate solutions of different precursors can also be used) is pumped into a vaporizer comprising a hot zone maintained at low pressure. In the vaporizer, the liquid solution is vaporized at high rate ("flash vaporized") under controlled temperature, pressure, and flow conditions. The vaporizer is advantageously flushed with solvent immediately before and after deposition to prevent accumulation of solid species that could cause clogging in the process equipment and associated piping, valves and fittings.
In the vaporizer, or downstream therefrom, the precursor vapor is combined with a carrier gas (e.g., argon or nitrogen) and an oxidizer (e.g., oxygen or nitrous oxide). The combined precursor vapor mixture then is flowed to the CVD deposition chamber.
The CVD deposition chamber is typically operated at low pressure, e.g., on the order of 100 millitorr, by deployment of a dry pump or wet pump on the discharge of the system. In such chamber, the precursors are decomposed on the heated substrate by a thermal reaction of the combined gases, organic vapors, and metalorganic precursors, resulting in the deposition of a thin perovskite film of BST material on the wafer substrate. After chemical deposition, the wafer coated with the BST film is transferred to a separate chamber for annealing.
The effluent from the CVD deposition chamber in the CVD BST process comprises organic species, metals, unreacted precursor, precursor decomposition species and other thermal reaction products deriving from the CVD operation.
Currently, there is no effective abatement scheme commercially available for the effluent of such CVD BST process.
The foregoing issues are not unique to the CVD BST process. They also apply to other multi-component metal oxides deposited by CVD processes using metal source reagent liquid solutions which comprise at least one metal coordination complex including a metal to which is coordinatively bound at least one ligand in a stable complex and a suitable solvent medium for that metal coordination complex. These include the multi-component metal oxide CVD processes using ligand exchange resistant metal-organic precursor solutions described in U.S. Pat. No. 5,820,664 issued Oct. 13, 1998 to Gardiner et al. and assigned to Advanced Technology Materials, Inc., Danbury, Conn.
SUMMARY OF THE INVENTION
The present invention relates to abatement of effluent produced by multi-component metal oxides deposited by CVD processes using metal source reagent liquid solutions which comprise at least one metal coordination complex including a metal to which is coordinatively bound at least one ligand in a stable complex and a suitable solvent medium for that metal coordination complex e.g., CVD of BST.
In one aspect, the invention relates to a method for abatement of effluent from a CVD process for depositing a multi-component metal oxide film on a substrate, in which the effluent is flowed through a sorbent bed having sorptive affinity for contaminant species (precursor species and CVD process by-products) in the effluent.
In a specific embodiment, effluent from the CVD process is flowed in sequence through a metals trap, a motive fluid driver, and a sorbent bed having sorptive affinity for contaminant species in the effluent.
The method may further comprise monitoring the effluent discharged from the sorbent bed, to detect breakthrough of a selected contaminant component.
The invention relates in another aspect to an apparatus for abatement of effluent from a CVD process for depositing multi-component metal oxide on a substrate from a precursor composition, wherein the apparatus comprises a sorbent bed having sorptive affinity for contaminants in the effluent. Such sorbent bed may be part of an effluent flow circuit including a metals trap, a motive fluid driver, and a sorbent bed having sorptive affinity for contaminants in the effluent, optionally equipped with an endpoint detector for detecting the endpoint of sorption of the sorbent bed.
The apparatus described above may further include a semiconductor manufacturing facility whose operation comprises the CVD process.
Other aspects, features and embodiments of the invention will be more fully apparent from the ensuing disclosure and appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic representation of an CVD multicomponent metal oxide film fabrication facility including an effluent abatement system according to one embodiment of the present invention.
DETAILED DESCRIPTION OF THE
INVENTION, AND PREFERRED
The present invention provides an effluent abatement system for treatment of effluent streams from multicomponent metal oxides deposited by CVD processes using metal source reagent liquid solutions which comprise at least