US4675984A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of exposing only the top surface of a mesa
Assignee: RCA Corp
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Filing: 1985-09-19
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Granted: 1987-06-30
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Expires: 2005-09-19
Abstract
Abstract A method of exposing only the top surface of a narrow mesa is disclosed wherein a protective layer may be very precisely formed on a very narrow mesa for subsequent doping of areas adjacent the mesa without doping the mesa itself. A variation of the invention includes forming an opening directly over the narrow mesa so that a contact may be made at only the top surface of the mesa or the upper portion of the mesa may be doped independent of surfaces adjacent the mesa.
Inventors
- 👤 Sheng T. Hsu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 12:26
CPC Classifications
H; H10; H10P; H10P76/00; H10P76/40; H10P14/00; H10P14/60; H10P14/69; H10P14/694; H10P14/6943; H10P14/69433; H10P50/00; H10P50/69; H10P50/691; Y; Y10; Y10S; Y10S148/00; Y10S148/05
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
128 words
In a method of making a semiconductor device, the steps of: (a) providing a mesa projecting from a first surface of said semiconductor device, said mesa having a top surface spaced from said first surface; (b) providing a first layer comprising a layer of high temperature dielectric and a layer of silicon nitride on and topographically conformal to said first surface and said mesa; (c) providing a planarizing second layer on said first layer, said second layer having a major surface that is substantially planar and approximately parallel to said first surface; and (d) planar etching said second layer to expose a portion of said first layer opposed to said mesa and removing said portion of said first layer to expose only said top surface of said mesa.
Claim 2
Dependent Claim
128 words
In a method of making a semiconductor device, the steps of: (a) providing a mesa projecting from a first surface of said semiconductor device, said mesa having a top surface spaced from said first surface; (b) providing a first layer comprising a layer of high temperature dielectric and a layer of silicon nitride on and topographically conformal to said first surface and said mesa; (c) providing a planarizing second layer on said first layer, said second layer having a major surface that is substantially planar and approximately parallel to said first surface; and (d) planar etching said second layer to expose a portion of said first layer opposed to said mesa and removing said portion of said first layer to expose only said top surface of said mesa.
Claim 3
Dependent Claim
70 words
The method set forth in claim 1 wherein said removing said portion of said first layer as set forth in step (d) includes the steps: (d1) planar etching only said portion of said first layer through one of said layer of high temperature dielectric or said layer of silicon nitride thereby exposing a portion of the other layer; and (d2) etching through only said exposed portion of said other layer.
Claim 4
Dependent Claim
29 words
The method set forth in claim 2 wherein said forming a layer of high temperature dielectric as set forth in step (b1) comprises depositing a layer of silicon oxide.
Claim 5
Dependent Claim
26 words
The method set forth in claim 3 wherein said depositing a layer of silicon oxide is performed prior to said forming a layer of silicon nitride.
References Cited (Backward Citations)
JPS5231686A
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US4518629A
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JPS59175135A
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JPS609140A
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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) | 1990-06-29 | 1990-12-29 | 1991-06-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-06-29 | 1994-12-29 | 1995-06-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-06-29 | 1998-12-29 | 1999-06-30 | $7700.00 | Window Closed / Lapsed |