US3962052A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for forming apertures in silicon bodies
Assignee: International Business Machines Corp
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Filing: 1975-04-14
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Granted: 1976-06-08
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Expires: 1995-04-14
Abstract
Abstract A process for forming holes with precisely controlled dimension and position in monocrystalline silicon wafers wherein the holes are fabricated with vertical sides. In the preferred process, both sides of the silicon body are masked, opposite registered openings made in the masking layers, an impurity introduced through the openings into the body forming low resistivity regions, the body anodically etched through the openings until a porous silicon region is formed completely through the body, and subsequently removing the resultant porous silicon region with a silicon etchant.
Inventors
- 👤 Shakir A. Abbas
- 👤 Robert C. Dockerty
- 👤 Michael R. Poponiak
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 13:59
CPC Classifications
B; B81; B81C; B81C1/00; B81C1/00015; B81C1/00023; B81C1/00087; H; H10; H10P; H10P50/00; H10P50/60; H10P50/61; H10P50/613; H10P50/69; H10P50/691; B81C2201/00; B81C2201/01; B81C2201/0101; B81C2201/0111; B81C2201/0115; Y; Y10; Y10S; Y10S438/00; Y10S438/914; Y10S438/924; Y10S438/96
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
88 words
A process for forming a hole through a monocrystalline silicon body comprising: forming masking layers on opposite sides of said body, forming opposite registering openings in said masking layers, introducing an impurity through said openings into said body forming low resistivity regions, depositing a conductive layer on one side of said body, anodically etching said body through the opening on the opposite side under conditions that form a region of porous silicon that extends completely through said body, and removing the resultant porous region with a silicon etchant.
Claim 2
Dependent Claim
88 words
A process for forming a hole through a monocrystalline silicon body comprising: forming masking layers on opposite sides of said body, forming opposite registering openings in said masking layers, introducing an impurity through said openings into said body forming low resistivity regions, depositing a conductive layer on one side of said body, anodically etching said body through the opening on the opposite side under conditions that form a region of porous silicon that extends completely through said body, and removing the resultant porous region with a silicon etchant.
Claim 3
Dependent Claim
22 words
The process of claim 1 wherein the surface of the resultant hole is oxidized forming an insulating layer of SiO 2 .
Claim 4
Dependent Claim
22 words
The process of claim 2 wherein impurities are introduced into said body through said registered openings from both sides of said body.
Claim 5
Dependent Claim
15 words
The process of claim 1 wherein said impurity is introduced by ion implantation or diffusion.
Claim 6
Dependent Claim
17 words
The process of claim 4 wherein said impurity is introduced into said body from only one side.
Claim 7
Dependent Claim
14 words
The process of claim 1 wherein said conductive layer is a layer of chromium.
Claim 8
Dependent Claim
24 words
The process of claim 1 wherein said impurity is introduced into said body to a depth in the range of one to 10 microns.
Claim 9
Dependent Claim
19 words
The process of claim 8 wherein said body has a thickness in the range of 100 to 375 microns.
Claim 10
Dependent Claim
20 words
The process of claim 1 wherein said body has an N-type background impurity and said introduced impurity is a P-type.
Claim 11
Dependent Claim
20 words
The process of claim 1 wherein said body has an N-type background impurity and the introduced impurity is an N-type.
Claim 12
Dependent Claim
20 words
The process of claim 1 wherein said body has a P-type background impurity and said introduced impurity is an N-type.
Claim 13
Dependent Claim
21 words
The process of claim 1 wherein said body has a P-type background impurity and said introduced impurity is a P-type impurity.
Claim 14
Dependent Claim
17 words
The process of claim 1 wherein said impurity is protons or helium implanted into an N-type body.
Claim 15
Dependent Claim
22 words
The process of claim 1 wherein said masking layers are formed by thermally oxidizing the top and bottom surfaces of said body.
Claim 16
Dependent Claim
17 words
The process of claim 1 wherein said masking layers are formed of Si 3 N 4 .
Claim 17
Dependent Claim
30 words
The process of claim 1 wherein the masking layer exposed to the anodizing solution is a layer of chromium on top of SiO 2 and/or Si 3 N 4 .
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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) | 1979-06-08 | 1979-12-08 | 1980-06-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-06-08 | 1983-12-08 | 1984-06-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-06-08 | 1987-12-08 | 1988-06-08 | $7700.00 | Window Closed / Lapsed |