US4488930A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing circular gallium arsenide wafer
Assignee: Sumitomo Electric Industries Ltd
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Filing: 1982-05-28
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Granted: 1984-12-18
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Expires: 2002-05-28
Abstract
Abstract A process for producing a circular gallium arsenide wafer including the steps of growing a gallium arsenide single-crystal boule in the form of a longitudinal half of a cylinder by the boat method in such a manner that the intersection of the flat surface produced by the boat method and the plane vertical to the direction of crystal growth extends in a <110> direction, slicing the boule into wafers to expose a (100) plane or a plane inclined within 0.5 to 5 degress with respect to the (100) plane, assembling the resulting triangular-like wafers into a triangular-like prism, grinding the opposite edges of the flat surface of the outer periphery of the triangular-like prism of wafers in a direction in which the wafers are assembled; and separating the triangular-like prism into discrete circular wafers.
Inventors
- 👤 Kiyohiko Koe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 17:38
CPC Classifications
B; B28; B28D; B28D5/00; B24; B24B; B24B1/00; B24B9/00; B24B9/02; B24B9/06; B24B9/065; C; C30; C30B; C30B29/00; C30B29/10; C30B29/40; C30B29/42; C30B33/00; H; H10; H10D; H10D62/00; H10D62/10; H10D62/117; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
152 words
A process for producing circular gallium arsenide wafers comprising the steps of: growing a gallium arsenide single-crystal boule in the form of a longitudinal half of cylinder by a boat method in such a manner that the intersection of a flat surface produced by the boat method and a plane vertical to the direction of the crystal growth extends in a <110> direction; slicing the boule into wafers to expose a (100) plane inclined by more than 0.5 degrees with respect to the (100) plane; assembling the resulting triangular wafers into a triangular prism; grinding the opposite edges of the flat surface of the outer periphery of said triangular prism of wafers in a direction in which the wafers are assembled and grinding away high dislocation density triangular portions of said prism, such that said prism is ground into a generally cylindrical form; and separating said triangular prism into discrete circular wafers.
Claim 2
Dependent Claim
152 words
A process for producing circular gallium arsenide wafers comprising the steps of: growing a gallium arsenide single-crystal boule in the form of a longitudinal half of cylinder by a boat method in such a manner that the intersection of a flat surface produced by the boat method and a plane vertical to the direction of the crystal growth extends in a <110> direction; slicing the boule into wafers to expose a (100) plane inclined by more than 0.5 degrees with respect to the (100) plane; assembling the resulting triangular wafers into a triangular prism; grinding the opposite edges of the flat surface of the outer periphery of said triangular prism of wafers in a direction in which the wafers are assembled and grinding away high dislocation density triangular portions of said prism, such that said prism is ground into a generally cylindrical form; and separating said triangular prism into discrete circular wafers.
Claim 3
Dependent Claim
27 words
The process of claim 1 wherein said plane produced by said step of slicing is inclined by 0.5 to 5 degrees with respect to the (100) plane.
Claim 4
Dependent Claim
30 words
The process of claim 1 wherein said step of assembling said resulting triangular wafer comprises adhering said wafers with a material selected from the group consisting of waxes and adhesives.
Claim 5
Dependent Claim
26 words
The process of claim 1 wherein said step of grinding comprises grinding said prism of wafers into a generally cylindrical form having a small flat area.
Claim 6
Dependent Claim
12 words
The process of claim 1 wherein said step of separating comprises heating.
Claim 7
Dependent Claim
14 words
The process of claim 1 wherein said step of separating comprises applying a solvent.
Claim 8
Dependent Claim
143 words
A process for producing circular gallium arsenide wafers comprising the steps of: growing a gallium arsenide single crystal boule in the form of a longitudinal half of a cylinder by a boat method in such a manner that the intersection of a flat surface produced by the boat method and a plane vertical to the direction of the crystal growth extends in a (100) direction; slicing the boule into wafers to expose a (100) plane; assembling the resulting substantially triangular wafers into a triangular prism; grinding the opposite edges of the flat surface of the outer periphery of said triangular prism of wafers in a direction in which the wafers are assembled and grinding away high dislocation density triangular portions of said prism, such that said prism is ground into a generally cylindrical form; and separating said triangular prism into discrete circular wafers.
Claim 9
Dependent Claim
143 words
A process for producing circular gallium arsenide wafers comprising the steps of: growing a gallium arsenide single crystal boule in the form of a longitudinal half of a cylinder by a boat method in such a manner that the intersection of a flat surface produced by the boat method and a plane vertical to the direction of the crystal growth extends in a (100) direction; slicing the boule into wafers to expose a (100) plane; assembling the resulting substantially triangular wafers into a triangular prism; grinding the opposite edges of the flat surface of the outer periphery of said triangular prism of wafers in a direction in which the wafers are assembled and grinding away high dislocation density triangular portions of said prism, such that said prism is ground into a generally cylindrical form; and separating said triangular prism into discrete circular wafers.
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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) | 1987-12-18 | 1988-06-18 | 1988-12-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-12-18 | 1992-06-18 | 1992-12-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-12-18 | 1996-06-18 | 1996-12-18 | $7700.00 | Window Closed / Lapsed |