US5419822A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for applying a thin adherent layer
Assignee: Raytheon Co
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Filing: 1989-02-28
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Granted: 1995-05-30
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Expires: 2009-02-28
Abstract
Abstract A method for applying an extremely thin layer of an adherent material to a substrate at a controllable rate. The disclosed embodiment provides a method for depositing a thin layer of titanium, typically much less than 100 Angstroms, on a silicon dioxide substrate layer in order to provide the necessary adhesion for a metallic film. A silicon wafer having a layer of silicon dioxide is placed on a titanium precoated carrier in an evacuated chamber. The wafer and carrier are then sputter etched using argon as a sputter etchant while titanium is deposited onto the wafer. The ratio of deposition rate to etching rate is controlled to provide a very low effective deposition rate. Thus, while the surface is being atomically cleaned, the adhesive layer is simultaneously deposited. A film of a noble metal, typically platinum, may then be deposited onto the adhesive layer. In an alternative embodiment, the titanium is sputter deposited from a target while the substrate is simultaneously sputter etched.
Inventors
- 👤 Sahag R. Dakesian
- 👤 William E. Wesolowski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 17:06
CPC Classifications
C; C23; C23C; C23C14/00; C23C14/06; C23C14/14; C23C14/18; C23C14/185; C23C14/02; C23C14/024; C23C14/025; C23C14/22; C23C14/50; C23C14/58; C23C14/5873
Claims Analysis
Total Claims: 34
Claim 1
Independent Claim
110 words
A method for applying a thin layer of a material to a substrate, comprising the steps of: a) providing a substrate holder having thereon a coating of said material; b) placing said substrate on said substrate holder in a chamber; c) reducing the background in said chamber to below a predetermined maximum contaminant level; and d) simultaneously etching said substrate while depositing said material on said substrate, the rate of deposition and the rate of etching being controllable, wherein the ratio of said rate of deposition to said rate of etching is such as to provide an effective deposition rate on said substrate of less than five Angstroms per minute.
Claim 2
Independent Claim
110 words
A method for applying a thin layer of a material to a substrate, comprising the steps of: a) providing a substrate holder having thereon a coating of said material; b) placing said substrate on said substrate holder in a chamber; c) reducing the background in said chamber to below a predetermined maximum contaminant level; and d) simultaneously etching said substrate while depositing said material on said substrate, the rate of deposition and the rate of etching being controllable, wherein the ratio of said rate of deposition to said rate of etching is such as to provide an effective deposition rate on said substrate of less than five Angstroms per minute.
Claim 3
Dependent Claim
12 words
The method according to claim 1 wherein said material comprises an adherent.
Claim 4
Dependent Claim
11 words
The method according to claim 1 wherein said material comprises titanium.
Claim 5
Dependent Claim
11 words
The method according to claim 1 wherein said substrate comprises silicon.
Claim 6
Dependent Claim
17 words
The method according to claim 4 wherein said silicon substrate further includes a layer of silicon dioxide.
Claim 7
Dependent Claim
24 words
The method according to claim 1 wherein said background reducing step comprises evacuating said chamber to a pressure no greater than 5×10 -7 Torr.
Claim 8
Dependent Claim
13 words
The method according to claim 1 wherein said etching step comprises sputter etching.
Claim 9
Dependent Claim
19 words
The method according to claim 7 wherein said sputter etching step is performed using argon gas as an etchant.
Claim 10
Dependent Claim
13 words
The method according to claim 1 wherein said depositing step comprises sputter depositing.
Claim 11
Dependent Claim
25 words
The method according to claim 9 wherein said coating is sputter etched from said substrate holder and is deposited on said substrate by back-scatter deposition.
Claim 12
Dependent Claim
43 words
The method according to claim 10 wherein the surface of said substrate holder onto which said substrate is placed has an area at least ten times greater than the area of the surface of said substrate onto which said material is sputter deposited.
Claim 13
Dependent Claim
32 words
The method according to claim 9 wherein said sputter depositing step comprises the step of sputtering a target of said material, the particles sputtered from said target being deposited on said substrate.
Claim 14
Dependent Claim
31 words
The method according to claim 1 wherein said deposition rate and said etching rate are controlled so as to provide an effective deposition rate of less than one Angstrom per minute.
Claim 15
Dependent Claim
31 words
The method according to claim 1 wherein said deposition rate and said etching rate are controlled so as to provide an effective deposition rate of less than 0.4 Angstrom per minute.
Claim 16
Independent Claim
117 words
A method for adhering a film to a substrate, comprising the steps of: a) providing a substrate holder having thereon a coating of an adherent material; b) placing said substrate on said substrate holder in a chamber; c) reducing the background in said chamber to below a predetermined maximum contaminant level; d) simultaneously etching said substrate while depositing said adherent material on said substrate, the rate of deposition and the rate of etching being controllable, wherein the ratio of said rate of deposition to said rate of etching is such as to provide an effective deposition rate on said substrate of less than five Angstroms per minute; and e) depositing said film onto said deposited adherent material.
Claim 17
Independent Claim
117 words
A method for adhering a film to a substrate, comprising the steps of: a) providing a substrate holder having thereon a coating of an adherent material; b) placing said substrate on said substrate holder in a chamber; c) reducing the background in said chamber to below a predetermined maximum contaminant level; d) simultaneously etching said substrate while depositing said adherent material on said substrate, the rate of deposition and the rate of etching being controllable, wherein the ratio of said rate of deposition to said rate of etching is such as to provide an effective deposition rate on said substrate of less than five Angstroms per minute; and e) depositing said film onto said deposited adherent material.
Claim 18
Dependent Claim
13 words
The method according to claim 15 wherein said film comprises a noble metal.
Claim 19
Dependent Claim
13 words
The method according to claim 16 wherein said noble metal film comprises platinum.
Claim 20
Dependent Claim
12 words
The method according to claim 15 wherein said adherent material comprises titanium.
Claim 21
Dependent Claim
11 words
The method according to claim 15 wherein said substrate comprises silicon.
Claim 22
Dependent Claim
17 words
The method according to claim 19 wherein said silicon substrate further includes a layer of silicon dioxide.
Claim 23
Dependent Claim
24 words
The method according to claim 15 wherein said background reducing step comprises evacuating said chamber to a pressure no greater than 5×10 -7 Torr.
Claim 24
Dependent Claim
13 words
The method according to claim 15 wherein said etching step comprises sputter etching.
Claim 25
Dependent Claim
19 words
The method according to claim 22 wherein said sputter etching step is performed using argon gas as an etchant.
Claim 26
Dependent Claim
13 words
The method according to claim 15 wherein said depositing step comprises sputter depositing.
Claim 27
Dependent Claim
25 words
The method according to claim 24 wherein said coating is sputter etched from said substrate holder and is deposited on said substrate by back-scatter deposition.
Claim 28
Dependent Claim
44 words
The method according to claim 25 wherein the surface of said substrate holder onto which said substrate is placed has an area at least ten times greater than the area of the surface of said substrate onto which said adherent material is sputter deposited.
Claim 29
Dependent Claim
32 words
The method according to claim 24 wherein said sputter depositing step comprises the step of sputtering a target of said material, the particles sputtered from said target being deposited on said substrate.
Claim 30
Dependent Claim
31 words
The method according to claim 15 wherein said deposition rate and said etching rate are controlled so as to provide an effective deposition rate of less than one Angstrom per minute.
Claim 31
Dependent Claim
31 words
The method according to claim 15 wherein said deposition rate and said etching rate are controlled so as to provide an effective deposition rate of less than 0.4 Angstrom per minute.
Claim 32
Dependent Claim
19 words
The method according to claim 15 wherein said film material is deposited onto said adherent material by sputter deposition.
Claim 33
Dependent Claim
62 words
The method according to claim 30 wherein said step of sputter depositing said film comprises the following substeps: f) sputter depositing said film material at a first power level during a first time duration; and g) sputter depositing said film material at a second power level, less than said first power level, during a second time duration, greater than said first duration.
Claim 34
Dependent Claim
18 words
The method according to claim 15 where said film material is deposited onto said adherent material by evaporation.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1998-05-29 | 1998-11-28 | 1999-05-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-05-29 | 2002-11-28 | 2003-05-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-05-29 | 2006-11-28 | 2007-05-30 | $7700.00 | Window Closed / Lapsed |