US3969168A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for filling grooves and moats used on semiconductor devices
Assignee: Motorola Solutions Inc
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Filing: 1974-11-29
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Granted: 1976-07-13
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Expires: 1994-11-29
Abstract
Abstract A process is disclosed for filling grooves, moats, and channels formed by both channel and anisotropic etching techniques. Basically the process is a two-step process to be performed on a wafer in which a channel and/or a moat has been formed. A P+ (boron) doped oxide is placed in the grooves or moats using spinon techniques followed by a uniform deposition of polycrystalline silicon over the entire wafer. Due to the spinning effects the P+ doped oxide is collected mostly in the grooves or moats. The P+ doped oxide that remains outside of the grooves and/or moats is removed using standard photolithographic procedures. The wafer is now heated to a temperature sufficient to drive the boron impurities from the P+ doped oxide into the polycrystalline silicon. A portion of a polycrystalline silicon now becomes heavily P+ doped. The remaining polycrystalline silicon remains undoped. The wafer is then etched by an etchant which effectively stops when the material being etched is highly P+ doped. In this manner a portion of the remaining undoped polycrystalline material is removed and the highly doped polycrystalline material is left in the channels and/or moats. The above can be repeated until the moats or channels are completely filled.
Inventors
- 👤 Gregory L. Kuhn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 22:14
CPC Classifications
H; H10; H10P; H10P32/00; H10P32/30; H10P32/302; H10P50/00; H10P50/60; H10P50/66; H10P50/663; H10P50/667; H10P95/00; H10W; H10W10/00; H10W10/01; H10W10/041; H10W10/40; Y; Y10; Y10S; Y10S148/00; Y10S148/043; Y10S148/051; Y10S148/085; Y10S148/118; Y10S148/122
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
89 words
A method for filling an evacuated space on a substrate with an insulating filler; providing a substrate having an upper surface and an evacuated space extending from said upper surface into the body of said substrate; forming an undoped silicon dioxide layer on said upper surface including said evacuated space; forming a highly P+ doped silicon layer on said upper surface including said evacuated space; and etchably removing said highly P+ doped silicon dioxide layer positioned on said surface, and leaving said highly doped oxide within said evacuated space.
Claim 2
Independent Claim
89 words
A method for filling an evacuated space on a substrate with an insulating filler; providing a substrate having an upper surface and an evacuated space extending from said upper surface into the body of said substrate; forming an undoped silicon dioxide layer on said upper surface including said evacuated space; forming a highly P+ doped silicon layer on said upper surface including said evacuated space; and etchably removing said highly P+ doped silicon dioxide layer positioned on said surface, and leaving said highly doped oxide within said evacuated space.
Claim 3
Dependent Claim
32 words
The method as recited in claim 1, wherein said step of forming a layer of undoped silicon dioxide further comprises: thermally oxidizing the substrate to form a layer of undoped silicon dioxide.
Claim 4
Independent Claim
102 words
A method for filling an evacuated space with an insulated filler on a substrate of the type which is able to withstand temperatures above 900°C, comprising the steps of: providing a substrate having an upper surface and an evacuated space extending from said upper surface into the body of said substrate; forming a layer of undoped silicon oxide on said surface including said evacuated space; forming a layer of P+ doped silicon oxide on said surface including said evacuated space; and etchably removing said P+ doped silicon oxide from said surface and leaving said P+ doped silicon oxide within said evacuated space.
Claim 5
Independent Claim
102 words
A method for filling an evacuated space with an insulated filler on a substrate of the type which is able to withstand temperatures above 900°C, comprising the steps of: providing a substrate having an upper surface and an evacuated space extending from said upper surface into the body of said substrate; forming a layer of undoped silicon oxide on said surface including said evacuated space; forming a layer of P+ doped silicon oxide on said surface including said evacuated space; and etchably removing said P+ doped silicon oxide from said surface and leaving said P+ doped silicon oxide within said evacuated space.
Claim 6
Dependent Claim
34 words
The method as recited in claim 3, wherein said step of forming the layer of undoped oxide further comprises: forming said layer of undoped oxide by thermally oxidizing said substrate at its oxidation temperature.
Claim 7
Dependent Claim
29 words
The method as recited in claim 3, wherein said step of forming the layer of undoped oxide further comprises: forming said layer of undoped oxide by chemical vapor deposition.
Claim 8
Dependent Claim
42 words
The method as recited in claim 4, wherein said step of forming the layer of P+ doped oxide further comprises: forming said layer of P+ doped oxide by spinning said P+ doped oxide onto the surface and evacuated space on said substrate.
Claim 9
Dependent Claim
31 words
The method as recited in claim 4, wherein said step of forming the layer of P+ doped oxide further comprises: forming said layer of P+ doped oxide by chemical vapor deposition.
Claim 10
Dependent Claim
41 words
The method as recited in claim 4, wherein said step of forming the layer of P+ doped oxide further comprises: forming said layer of P+ doped oxide by spraying said P+ doped oxide over said upper surface including said evacuated space.
Claim 11
Dependent Claim
31 words
The method as recited in claim 5, wherein said step of forming the layer of P+ doped oxide further comprises: forming said layer of P+ doped oxide by chemical vapor deposition.
Claim 12
Dependent Claim
40 words
The method as recited in claim 5, wherein said step of forming the layer of P+ doped oxide further comprises: forming said P+ doped oxide by spinning said P+ doped oxide onto the surface and evacuated space on said substrate.
Claim 13
Dependent Claim
41 words
The method as recited in claim 5, wherein said step of forming the layer of P+ doped oxide further comprises: forming said layer of P+ doped oxide by spraying said P+ doped oxide over said upper surface including said evacuated space.
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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) | 1979-07-13 | 1980-01-12 | 1980-07-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-07-13 | 1984-01-12 | 1984-07-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-07-13 | 1988-01-12 | 1988-07-13 | $7700.00 | Window Closed / Lapsed |