Patent US4081928A successfully refreshed from Google Patents.
US4081928A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Silicon slice carrier block and plug assembly
Assignee: Texas Instruments Inc
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Filing: 1976-08-17
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Granted: 1978-04-04
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Expires: 1996-08-17
Abstract
Abstract A carrier block and plug assembly for use in polishing semiconductor slices and includes a block of stainless steel onto which is secured a Delrin retainer with Delrin plugs seated on the block and within the retainer. A Mylar spacer of variable predetermined thickness is positioned between the block and retainer and around the plugs. The bottom side of the block as well as the top sides of the plug and retainer are machined to be parallel to each other. The thickness of the spacer determines the amount of the slice protruding above the retainer, thickness being based upon the thickness of the slice being polished. The slice is placed over a plug after water or other appropriate liquid has been placed on the plug or slice to provide adhesion of the slice to the plug by surface tension, whereby the slice can freely rotate on the plug and within the retainer during polishing. Polishing takes place by mounting the block on a rotating device which rotates over and against a standard polishing pad, both block and pad rotates in the same direction. The pad is flat and parallel to the retainer surface. The slices are removed from the block after polishing by immersion in water to diminish the surface tension.
Inventors
- 👤 Gerald P. Kinnebrew
- 👤 Bobby Mack Watkins
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 20:10
CPC Classifications
H; H10; H10P; H10P90/00; H10P90/12; H10P90/129; B; B24; B24B; B24B37/00; B24B37/27; C; C30; C30B; C30B33/00
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
178 words
A carrier block and plug assembly for retaining semiconductor slices for polishing which comprises: (a) a rigid block having a planar surface, (b) a retainer having parallel opposite surfaces and a plurality of apertures extending therethrough, said apertures having the same diameter throughout, (c) a spacer positioned between said block and retainer in the non-apertured region, (d) a plurality of plugs secured to said block and extending into said apertures, said plugs having substantially the same diameter as said apertures and substantially the same thickness as said retainer, thereby defining pockets having a uniform depth equal to the thickness of said spacer, said plugs each comprising means for supporting a wet semiconductor slice for free rotation thereon and consisting essentially of a rigid plastic material which is nonabsorptive and retains its shape at elevated temperatures, each plug having only a single surface exposed within its corresponding aperture, said plug surface being planar and having a high lubricity, (e) means securing said block to said retainer, (f) the exposed surfaces of said block, retainer and plugs being mutually parallel.
Claim 2
Dependent Claim
178 words
A carrier block and plug assembly for retaining semiconductor slices for polishing which comprises: (a) a rigid block having a planar surface, (b) a retainer having parallel opposite surfaces and a plurality of apertures extending therethrough, said apertures having the same diameter throughout, (c) a spacer positioned between said block and retainer in the non-apertured region, (d) a plurality of plugs secured to said block and extending into said apertures, said plugs having substantially the same diameter as said apertures and substantially the same thickness as said retainer, thereby defining pockets having a uniform depth equal to the thickness of said spacer, said plugs each comprising means for supporting a wet semiconductor slice for free rotation thereon and consisting essentially of a rigid plastic material which is nonabsorptive and retains its shape at elevated temperatures, each plug having only a single surface exposed within its corresponding aperture, said plug surface being planar and having a high lubricity, (e) means securing said block to said retainer, (f) the exposed surfaces of said block, retainer and plugs being mutually parallel.
Claim 3
Dependent Claim
35 words
An assembly as set forth in claim 1 wherein said outer surface of said plug is positioned below the outer surface of said retainer by a distance substantially equal to the thickness of the spacer.
Claim 4
Dependent Claim
34 words
An assembly as set forth in claim 1 wherein said apertures are circular in cross-section and said plugs are circular and has a diameter substantially the same as the cross-sectional diameter of said apertures.
Claim 5
Dependent Claim
34 words
An assembly as set forth in claim 2 wherein said apertures are circular in cross-section and said plugs are circular and have a diameter substantially the same as the cross-sectional diameter of said apertures.
Claim 6
Dependent Claim
80 words
An assembly as set forth in claim 1 wherein said block retains its shape within the temperature range of the polishing operation, said retainer and plugs are formed from a material having a thermal coefficient of expansion substantially no greater than stainless steel, substantially no water absorption and being rigid but softer than the semiconductor material to be polished and said spacer being formed from a material which is rigid, not compressable and capable of having an accurately controlled thickness.
Claim 7
Dependent Claim
80 words
An assembly as set forth in claim 2 wherein said block retains its shape within the temperature range of the polishing operation, said retainer and plugs are formed from a material having a thermal coefficient of expansion substantially no greater than stainless steel, substantially no water absorption and being rigid but softer than the semiconductor material to be polished and said spacer being formed from a material which is rigid, not compressable and capable of having an accurately controlled thickness.
Claim 8
Dependent Claim
80 words
An assembly as set forth in claim 3 wherein said block retains its shape within the temperature range of the polishing operation, said retainer and plugs are formed from a material having a thermal coefficient of expansion substantially no greater than stainless steel, substantially no water absorption and being rigid but softer than the semiconductor material to be polished and said spacer being formed from a material which is rigid, not compressable and capable of having an accurately controlled thickness.
Claim 9
Dependent Claim
80 words
An assembly as set forth in claim 4 wherein said block retains its shape within the temperature range of the polishing operation, said retainer and plugs are formed from a material having a thermal coefficient of expansion substantially no greater than stainless steel, substantially no water absorption and being rigid but softer than the semiconductor material to be polished and said spacer being formed from a material which is rigid, not compressable and capable of having an accurately controlled thickness.
Claim 10
Dependent Claim
30 words
An assembly as set forth in claim 5 wherein each of said block, plugs, retainer and spacer are formed from a material substantially resistant to pH values of about 12.5.
Claim 11
Dependent Claim
30 words
An assembly as set forth in claim 6 wherein each of said block, plugs, retainer and spacer are formed from a material substantially resistant to pH values of about 12.5.
Claim 12
Dependent Claim
30 words
An assembly as set forth in claim 7 wherein each of said block, plugs, retainer and spacer are formed from a material substantially resistant to pH values of about 12.5.
Claim 13
Dependent Claim
30 words
An assembly as set forth in claim 8 wherein each of said block, plugs, retainer and spacer are formed from a material substantially resistant to pH values of about 12.5.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-04-03 | 1981-10-03 | 1982-04-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-04-03 | 1985-10-03 | 1986-04-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-04-03 | 1989-10-03 | 1990-04-04 | $7700.00 | Window Closed / Lapsed |