Patent US5441591A successfully refreshed from Google Patents.
US5441591A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Silicon to sapphire bond
Assignee: United States Department of the Navy
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Filing: 1993-06-07
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Granted: 1995-08-15
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Expires: 2013-06-07
Abstract
Abstract A method of bonding silicon to sapphire may be performed at room temperature and with no greater pressure than that due to one wafer resting on another. The method comprises the steps of polishing one side of a flat sapphire wafer to a mirror-like surface; polishing one side of a flat silicon wafer to a mirror-like surface; cleaning the wafers and then stacking the wafers so that their corresponding mirror-like surfaces contact. The room temperature bonding that occurs is relatively strong, and the bonded wafers can be handled without danger of their becoming unbonded. If desired, the bonded wafers may be subjected to further processing to further strengthen their bond.
Inventors
- 👤 George P. Imthurn
- 👤 Howard Walker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 01:58
CPC Classifications
H; H10; H10P; H10P90/00; H10P90/19; H10P90/1904; H10P90/1906; H10P90/1914; Y; Y10; Y10S; Y10S148/00; Y10S148/012; Y10S148/135; Y10S148/15
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
86 words
A method for bonding silicon to sapphire without the addition of heat and comprising the steps of: directly polishing one side of a sapphire wafer to a mirror surface; directly polishing one side of a silicon wafer to a mirror surface; cleaning said wafers; and stacking said wafers so that said mirror surfaces make contact directly without oxide therebetween and without any pressure greater than that due to one wafer resting on another whereby a bond between said silicon wafer and said sapphire wafer is formed.
Claim 2
Independent Claim
86 words
A method for bonding silicon to sapphire without the addition of heat and comprising the steps of: directly polishing one side of a sapphire wafer to a mirror surface; directly polishing one side of a silicon wafer to a mirror surface; cleaning said wafers; and stacking said wafers so that said mirror surfaces make contact directly without oxide therebetween and without any pressure greater than that due to one wafer resting on another whereby a bond between said silicon wafer and said sapphire wafer is formed.
Claim 3
Dependent Claim
21 words
A method according to claim 1 in which the step of cleaning said wafers includes using hydrogen peroxide and ammonium hydroxide.
Claim 4
Dependent Claim
27 words
A method according to claim 1 in which said cleaning step is followed by a rinse in de-ionized water followed by a drying step utilizing heated nitrogen.
Claim 5
Dependent Claim
16 words
A method according to claim 1 in which said cleaning step further includes using hydrofluoric acid.
Claim 6
Dependent Claim
27 words
A method according to claim 4 in which said cleaning step is followed by a rinse in de-ionized water followed by a drying step utilizing heated nitrogen.
Claim 7
Dependent Claim
19 words
A method according to claim 1 in which said silicon wafer and said sapphire wafer are not latticed matched.
Claim 8
Dependent Claim
14 words
A method according to claim 1 in which said bonding occurs at room temperature.
Claim 9
Dependent Claim
20 words
A method according to claim 1 in which said bonded silicon and sapphire wafers are used in an electro-optical environment.
Claim 10
Dependent Claim
15 words
A method according to claim 1 further including the step of pressing said wafers together.
Claim 11
Independent Claim
83 words
A method for bonding silicon to sapphire without the addition of heat and comprising the steps of: directly polishing one side of a sapphire wafer to a mirror surface; directly polishing one side of a silicon wafer to a mirror surface; and stacking said wafers so that said mirror surfaces make contact directly without oxide therebetween and without any pressure greater than that: due to one wafer resting on another whereby a bond between said silicon wafer and said sapphire wafer is formed.
Claim 12
Independent Claim
83 words
A method for bonding silicon to sapphire without the addition of heat and comprising the steps of: directly polishing one side of a sapphire wafer to a mirror surface; directly polishing one side of a silicon wafer to a mirror surface; and stacking said wafers so that said mirror surfaces make contact directly without oxide therebetween and without any pressure greater than that: due to one wafer resting on another whereby a bond between said silicon wafer and said sapphire wafer is formed.
Claim 13
Dependent Claim
17 words
A method for bonding silicon-to-sapphire according to claim 10 in which said bonding occurs at room temperature.
Claim 14
Dependent Claim
20 words
A method according to claim 10 in which said bonded silicon and sapphire wafers are used in an electro-optical environment.
Claim 15
Dependent Claim
19 words
A method according to claim 10 in which said silicon wafer and said sapphire wafer are not latticed matched.
Claim 16
Dependent Claim
15 words
A method according to claim 10 further including the step of pressing said wafers together.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-08-14 | 1999-02-13 | 1999-08-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-08-14 | 2003-02-13 | 2003-08-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-08-14 | 2007-02-13 | 2007-08-15 | $7700.00 | Window Closed / Lapsed |