US3616348A
Expired / Lapsed
US
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Process for isolating semiconductor elements
Assignee: RCA Corp
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Filing: 1968-06-10
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Granted: 1971-10-26
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Expires: 1988-06-10
Abstract
Abstract In the manufacture of beam lead integrated circuits or discrete devices, each operating semiconductor portion of one conductivity type is surrounded by substrate material of opposite conductivity type. The substrate material is removed by a preferential electrolytic etching process to provide isolation between each of the semiconductor-operating portions.
Inventors
- 👤 William J Greig
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 05:37
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/60; H10P50/61; H10P50/613; H10W; H10W10/00; H10W10/01; H10W10/021; H10W10/20; H10W20/00; H10W20/40; Y; Y10; Y10S; Y10S148/00; Y10S148/051; Y10S148/085; Y10S438/00; Y10S438/914; Y10S438/924
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
31 words
A process according to claim 1 wherein said metallic interconnection contacts a substrate exposed surface portiOn outside said first regions, and the voltage is applied to said substrate via said interconnection.
Claim 2
Dependent Claim
30 words
A process according to claim 1 wherein said openings expose surface portions of said second regions, and said metallic interconnection seals said second region exposed surface portions against said etchant.
Claim 3
Dependent Claim
20 words
A process according to claim 1, wherein said interconnection provides both electrical and mechanical coupling between said two first regions.
Claim 4
Dependent Claim
14 words
A process according to claim 1, wherein said semiconductor body is of P-type conductivity.
Claim 5
Dependent Claim
24 words
A process according to claim 5, wherein said etched semiconductor body comprises silicon and said etching solution comprises hydrofluoric acid, acetic acid and water.
Claim 6
Dependent Claim
132 words
A semiconductor device manufacturing process comprising the steps of: providing a substrate comprising a body of semiconductor material of one conductivity type covered by an epitaxial layer of opposite conductivity type; forming rings of said one conductivity type extending entirely through said epitaxial layer, the portions of said epitaxial layer within said rings comprising spaced apart regions of opposite conductivity type; forming in each of said regions at least one semiconductor element having at least one contact area at a surface of said epitaxial layer; providing a metallic layer on said surface extending between and electrically coupled to said contact areas; and immersing said substrate in an electrically conductive etching solution and applying a voltage between said rings and said solution to etch said material of one conductivity type outside said regions.
Claim 7
Dependent Claim
26 words
A process according to claim 7, wherein said metallic layer is of sufficient thickness to provide mechanical as well as electrical coupling between the contact areas.
Claim 8
Dependent Claim
18 words
A process according to claim 8, wherein said semiconductor body and said isolating rings are of P-type conductivity.
Claim 9
Dependent Claim
37 words
A process according to claim 9, wherein the conductivity type determining impurity concentration within each of said isolating rings is substantially greater than the conductivity type determining impurity concentration within the adjacent part of each corresponding region.
Claim 10
Dependent Claim
41 words
A process according to claim 8, wherein said preferential etching step comprises: contacting said layer with each of said isolating rings; and applying a voltage between said layer and said etching solution to preferentially etch said semiconductor body and isolating rings.
Claim 11
Dependent Claim
17 words
A process according to claim 11, wherein said semiconductor body and isolating rings are of P-type conductivity.
Claim 12
Dependent Claim
19 words
A process according to claim 12, wherein said etching solution comprises an aqueous solution of hydrofluoric and acetic acids.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-10-25 | 1975-04-26 | 1975-10-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-10-25 | 1979-04-26 | 1979-10-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-10-25 | 1983-04-26 | 1983-10-26 | $7700.00 | Window Closed / Lapsed |