US5801084A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Bonded wafer processing
Assignee: Intersil Corp
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Filing: 1997-04-14
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Granted: 1998-09-01
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Expires: 2017-04-14
Abstract
Abstract Warpage in a bonded wafer is limited by maintenance of a stress compensation layer on the backside of the bonded wafer during device fabrication processing. One embodiment applies a sacrificial polysilicon layer over a stress compensation silicon dioxide layer for bonded silicon wafers. The fabrication processing consumes the polysilicon layer but not the stress compensation silicon dioxide.
Inventors
- 👤 James Douglas Beasom
- 👤 Craig James McLachlan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 21:09
CPC Classifications
H; H10; H10W; H10W10/00; H10P; H10P90/00; H10P90/19; H10P90/1904; H10P90/1906; H10P95/00; H10W10/01; H10W10/061; H10W10/10; H10W10/181; H10P90/1914; H10W10/041; H10W10/40; Y; Y10; Y10S; Y10S148/00; Y10S148/012; Y10S148/05; Y10S438/00; Y10S438/938
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
118 words
A method for preparing a plurality of bonded wafers for contact with vacuum wafer chucks comprising the steps of providing a plurality of device wafers and a plurality of handle wafers suitable for bonding to one another; bonding each device wafer to a first surface of a handle wafer with an oxide layer between said wafers; providing a stress compensation layer along a second surface of each handle wafer, said stress compensation layer generating a net residual stress for concavely warping the bonded wafer along the second surface of said handle wafer; and placing each bonded wafer on a vacuum wafer chuck such that the concave second surface of the handle wafer makes contact with the wafer chuck.
Claim 2
Independent Claim
118 words
A method for preparing a plurality of bonded wafers for contact with vacuum wafer chucks comprising the steps of providing a plurality of device wafers and a plurality of handle wafers suitable for bonding to one another; bonding each device wafer to a first surface of a handle wafer with an oxide layer between said wafers; providing a stress compensation layer along a second surface of each handle wafer, said stress compensation layer generating a net residual stress for concavely warping the bonded wafer along the second surface of said handle wafer; and placing each bonded wafer on a vacuum wafer chuck such that the concave second surface of the handle wafer makes contact with the wafer chuck.
Claim 3
Dependent Claim
15 words
The method of claim 1 further comprising forming a protection layer over stress compensation layer.
Claim 4
Dependent Claim
22 words
The method of claim 1 wherein each wafer is further processed for integrated circuit formation by repeated placement on a wafer chuck.
Claim 5
Dependent Claim
25 words
The method of claim 3 wherein throughout processing the curvature is concave along the surface of the bonded wafer closest to the stress compensation layer.
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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) | 2001-08-31 | 2002-03-02 | 2002-09-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-08-31 | 2006-03-02 | 2006-09-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-08-31 | 2010-03-02 | 2010-09-01 | $7700.00 | Window Closed / Lapsed |