Patent US4962879A successfully refreshed from Google Patents.
US4962879A
Expired / Lapsed
US
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Method for bubble-free bonding of silicon wafers
Assignee: Duke University
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Filing: 1989-09-25
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Granted: 1990-10-16
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Expires: 2009-09-25
Abstract
Abstract A method for bubble-free bonding of silicon wafers to silicon wafers or silicon wafers to quartz wafers either outside or inside a Clean Room. The method includes the steps of positioning wafers in closely spaced-apart and parallel relationship to each other in a rack or the like with mirror-polished surfaces of the wafers facing each other, cleansing the mirror-polished surfaces with a hydrophilization cleansing solution, flushing the cleansing solution from the mirror-polished surfaces of the wafers with deionized water, drying the wafers in a spin-dryer, and moving the wafers together so that contact occurs between opposing mirror-polished surfaces of the wafers and bonding occurs. The bonded wafers are then placed into a wafer shipping and storing container for improved wafer storage performance.
Inventors
- 👤 Ulrich M. Goesele
- 👤 Volker Lehmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 01:11
CPC Classifications
H; H10; H10P; H10P70/00; H10P70/10; H10P70/15; H10P10/00; H10P10/12; H10P10/128; H10P90/00; H10P90/19; H10P90/1904; H10P90/1906; H10P90/1914; H10W; H10W72/00; H10W72/30; H10W72/071; H10W72/073; H10W72/07331; H10W72/07337; Y; Y10; Y10S; Y10S228/00; Y10S228/903; Y10S438/00; Y10S438/974
Claims Analysis
Total Claims: 41
Claim 1
Independent Claim
169 words
A method for bonding at least two wafers and storing the bonded wafers in a wafer container wherein said at least two wafers includes at least one first wafer comprising silicon and at least one second wafer comprising either silicon or glass wherein each of said wafers has at least one mirror-polished surface, including the steps of: positioning said first and second wafers in closely spaced-apart and parallel relationship to each other and with each of said wafers having a mirror-polished surface opposing a mirror-polished surface of the other wafer; introducing a cleansing solution onto the opposing mirror-polished surfaces of said first and second wafers; flushing said cleansing solution from said mirror-polished surfaces of said first and second wafers; drying said mirror-polished surfaces of said first and second wafers; moving said first and second wafers together so that contact occurs between said opposing mirror-polished surfaces of said first and second wafers; and placing a plurality of said bonded first and second wafers into a wafer shipping and storage container.
Claim 2
Independent Claim
169 words
A method for bonding at least two wafers and storing the bonded wafers in a wafer container wherein said at least two wafers includes at least one first wafer comprising silicon and at least one second wafer comprising either silicon or glass wherein each of said wafers has at least one mirror-polished surface, including the steps of: positioning said first and second wafers in closely spaced-apart and parallel relationship to each other and with each of said wafers having a mirror-polished surface opposing a mirror-polished surface of the other wafer; introducing a cleansing solution onto the opposing mirror-polished surfaces of said first and second wafers; flushing said cleansing solution from said mirror-polished surfaces of said first and second wafers; drying said mirror-polished surfaces of said first and second wafers; moving said first and second wafers together so that contact occurs between said opposing mirror-polished surfaces of said first and second wafers; and placing a plurality of said bonded first and second wafers into a wafer shipping and storage container.
Claim 3
Dependent Claim
20 words
A method according to claim 1 wherein said plurality of bonded first and second wafers are spaced-apart in said container.
Claim 4
Dependent Claim
22 words
A method according to claim 1 wherein said plurality of bonded first and second wafers are positioned in contact in said container.
Claim 5
Dependent Claim
22 words
A method according to claim 1 wherein said first wafer is a silicon wafer and said second wafer is a silicon wafer.
Claim 6
Dependent Claim
22 words
A method according to claim 1 wherein said first wafer is a silicon wafer and said second wafer is a glass wafer.
Claim 7
Dependent Claim
14 words
A method according to claim 5 wherein said glass wafer is a quartz wafer.
Claim 8
Dependent Claim
29 words
A method according to claim 1 wherein said first and second wafers are maintained in said spaced-apart relationship by inert spacer elements positioned adjacent the perimeter of said wafers.
Claim 9
Dependent Claim
20 words
A method according to claim 7 wherein said spacer elements maintain a distance of about 10-1,000 μm between said wafers.
Claim 10
Dependent Claim
40 words
A method according to claim 1 wherein said cleansing solution is a hydrophilization bath comprising by volume about 55% H 2 O, 9% H 2 O 2 and 36% NH 4 OH at a temperature of about 50° C.-60° C.
Claim 11
Dependent Claim
19 words
A method according to claim 9 wherein said wafers are immersed in said hydrophilization bath for about 2-5 minutes.
Claim 12
Dependent Claim
17 words
A method according to claim 1 wherein said wafers are flushed with a stream of filtered water.
Claim 13
Dependent Claim
14 words
A method according to claim 1 wherein said wafers are flushed with deionized water.
Claim 14
Dependent Claim
13 words
A method according to claim 1 wherein said wafers are dried by spin-drying.
Claim 15
Dependent Claim
28 words
A method according to claim 13 wherein said wafers are heated with an infrared lamp to a temperature of about 45° C. or more during said spin-drying process.
Claim 16
Independent Claim
199 words
A method for bonding at least two wafers and storing the bonded wafers in a wafer container wherein said at least two wafers includes at least one first wafer comprising silicon and at least one second wafer comprising either silicon or glass wherein each of said wafers has at least one mirror-polished surface, including the steps of: positioning said first and second wafers in closely spaced-apart and parallel relationship to each other with inert spacer elements adjacent the perimeter of said wafers and with each of said wafers having a mirror-polished surface opposing a mirror-polished surface of the other wafer; introducing a hydrophilization cleansing solution onto the opposing mirror-polished surfaces of said first and second wafers; flushing said cleansing solution from said mirror-polished surfaces of said first and second wafers with deionized water; spin-drying said mirror-polished surfaces of said first and second wafers; removing said spacer elements from contact with the perimeter of said first and second wafers and moving said first and second wafers together so that contact occurs between said opposing mirror-polished surfaces of said first and second wafers; and placing a plurality of said bonded first and second wafers into a wafer shipping and storage container.
Claim 17
Independent Claim
199 words
A method for bonding at least two wafers and storing the bonded wafers in a wafer container wherein said at least two wafers includes at least one first wafer comprising silicon and at least one second wafer comprising either silicon or glass wherein each of said wafers has at least one mirror-polished surface, including the steps of: positioning said first and second wafers in closely spaced-apart and parallel relationship to each other with inert spacer elements adjacent the perimeter of said wafers and with each of said wafers having a mirror-polished surface opposing a mirror-polished surface of the other wafer; introducing a hydrophilization cleansing solution onto the opposing mirror-polished surfaces of said first and second wafers; flushing said cleansing solution from said mirror-polished surfaces of said first and second wafers with deionized water; spin-drying said mirror-polished surfaces of said first and second wafers; removing said spacer elements from contact with the perimeter of said first and second wafers and moving said first and second wafers together so that contact occurs between said opposing mirror-polished surfaces of said first and second wafers; and placing a plurality of said bonded first and second wafers into a wafer shipping and storage container.
Claim 18
Dependent Claim
20 words
A method according to claim 15 wherein said plurality of bonded first and second wafers are spaced-apart in said container.
Claim 19
Dependent Claim
22 words
A method according to claim 15 wherein said plurality of bonded first and second wafers are positioned in contact in said container.
Claim 20
Dependent Claim
22 words
A method according to claim 15 wherein said first wafer is a silicon wafer and said second wafer is a silicon wafer.
Claim 21
Dependent Claim
22 words
A method according to claim 15 wherein said first wafer is a silicon wafer and said second wafer is a glass wafer.
Claim 22
Dependent Claim
14 words
A method according to claim 19 wherein said glass wafer is a quartz wafer.
Claim 23
Dependent Claim
21 words
A method according to claim 15 wherein said inert spacer elements maintain a distance of about 10-1,000 μm between said wafers.
Claim 24
Dependent Claim
40 words
A method according to claim 15 wherein said hydrophilization cleansing solution is a bath comprising by volume about 55% H 2 O, 9% H 2 O 2 and 36% NH 4 OH at a temperature of about 50° C.-60° C.
Claim 25
Dependent Claim
18 words
A method according to claim 22 wherein said wafers are immersed in said bath for about 2-5 minutes.
Claim 26
Dependent Claim
28 words
A method according to claim 15 wherein said wafers are heated with an infrared lamp to a temperature of about 45° C. or more during said spin-drying process.
Claim 27
Independent Claim
151 words
A method for bonding at least two wafers and storing the bonded wafers in a wafer container wherein said at least two wafers includes at least one first semiconductor wafer and at least one second wafer comprising either a semiconductor material or glass wherein each of said wafers has at least one mirror-polished surface, including the steps of: positioning said first and second wafers in closely spaced-apart and parallel relationship to each other and with each of said wafers having a mirror-polished surface opposing a mirror-polished surface of the other wafer; cleansing said mirror-polished surfaces of said first and second wafers; drying said mirror-polished surfaces of said first and second wafers; moving said first and second wafers together so that contact occurs between said opposing mirror-polished surfaces of said first and second wafers; and placing a plurality of said bonded first and second wafers into a wafer shipping and storage container.
Claim 28
Independent Claim
151 words
A method for bonding at least two wafers and storing the bonded wafers in a wafer container wherein said at least two wafers includes at least one first semiconductor wafer and at least one second wafer comprising either a semiconductor material or glass wherein each of said wafers has at least one mirror-polished surface, including the steps of: positioning said first and second wafers in closely spaced-apart and parallel relationship to each other and with each of said wafers having a mirror-polished surface opposing a mirror-polished surface of the other wafer; cleansing said mirror-polished surfaces of said first and second wafers; drying said mirror-polished surfaces of said first and second wafers; moving said first and second wafers together so that contact occurs between said opposing mirror-polished surfaces of said first and second wafers; and placing a plurality of said bonded first and second wafers into a wafer shipping and storage container.
Claim 29
Dependent Claim
20 words
A method according to claim 25 wherein said plurality of bonded first and second wafers are spaced-apart in said container.
Claim 30
Dependent Claim
22 words
A method according to claim 25 wherein said plurality of bonded first and second wafers are positioned in contact in said container.
Claim 31
Dependent Claim
22 words
A method according to claim 25 wherein said first wafer is a silicon wafer and said second wafer is a silicon wafer.
Claim 32
Dependent Claim
22 words
A method according to claim 25 wherein said first wafer is a silicon wafer and said second wafer is a glass wafer.
Claim 33
Dependent Claim
14 words
A method according to claim 29 wherein said glass wafer is a quartz wafer.
Claim 34
Dependent Claim
17 words
A method according to claim 25 wherein said wafers are spaced-apart about 10-1,000 μm from each other.
Claim 35
Dependent Claim
44 words
A method according to claim 25 wherein the mirror-polished surfaces of said first and second wafers have been subjected to a hydrophilization treatment by the wafer manufacturer and said cleansing step comprises flushing said mirror-polished surfaces of said first and second wafers with water.
Claim 36
Dependent Claim
41 words
A method according to claim 25 wherein said cleansing step comprises introducing a cleansing solution onto the opposing mirror-polished surfaces of said first and second wafers and flushing said cleansing solution from said mirror-polished surfaces of said first and second wafers.
Claim 37
Dependent Claim
40 words
A method according to claim 33 wherein said cleansing solution is a hydrophilization bath comprising by volume about 55% H 2 O, 9% H 2 O 2 and 36% NH 4 OH at a temperature of about 50° C.-60° C.
Claim 38
Dependent Claim
19 words
A method according to claim 34 wherein said wafers are immersed in said hydrophilization bath for about 2-5 minutes.
Claim 39
Dependent Claim
17 words
A method according to claim 33 wherein said wafers are flushed with a stream of deionized water.
Claim 40
Dependent Claim
13 words
A method according to claim 25 wherein said wafers are dried by spin-drying.
Claim 41
Dependent Claim
28 words
A method according to claim 37 wherein said wafers are heated with an infrared lamp to a temperature of about 45° C. or more during said spin-drying process.
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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) | 1993-10-15 | 1994-04-16 | 1994-10-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-10-15 | 1998-04-16 | 1998-10-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-10-15 | 2002-04-16 | 2002-10-16 | $7700.00 | Window Closed / Lapsed |