US5597738A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for forming isolated CMOS structures on SOI structures
Assignee: Kulite Semiconductor Products Inc
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Filing: 1995-03-06
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Granted: 1997-01-28
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Expires: 2015-03-06
Abstract
Abstract A method for fabricating a single crystal silicon on insulator material by forming oxidized layers underneath epi islands without damaging the surface quality of the silicon. In an illustrative embodiment, an epitaxial layer of p-type silicon is grown on a substrate of n-type silicon. A plurality of islands are defined from the epitaxial layer. A semiconductor device is fabricated from one of the p-islands by electrochemically anodizing a region of the substrate beneath that p-island, which p-island can be used to fabricate a selected semiconductor device. If n-type material is required for device fabrication, a device layer of n-type silicon can be grown on the surface of a p-islands and that p-island can be anodized and oxidized to form the insulating layer between the device layer and substrate. In this manner, MOS transistors and other devices may be fabricated for operation at temperatures of up to 500° C.
Inventors
- 👤 Anthony D. Kurtz
- 👤 Joseph S. Shor
- 👤 Alexander A. Ned
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 02:36
CPC Classifications
H; H10; H10P; H10P90/00; H10P90/19; H10P90/1904; H10P90/1906; H10W; H10W10/00; H10W10/01; H10W10/021; H10W10/061; H10W10/10; H10W10/181; H10W10/20; Y; Y10; Y10S; Y10S148/00; Y10S148/15; Y10S148/152
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
115 words
A method of fabricating a silicon-on-insulated conductor structure for semiconductor integrated circuits, comprising the steps of: providing a substrate of semiconductor material of a first conductivity type having a substantially smooth and trenchless first side and a second side; depositing a first layer of semiconducting material of a second conductivity type directly on all of said first side of said substrate; defining a plurality of islands in said first layer; growing a second layer of said semiconducting material on at least one of said islands, said second layer being of said first conductivity type; forming a porous region beneath said at least one island; and selectively oxidizing said porous region to form an isolating layer.
Claim 2
Independent Claim
115 words
A method of fabricating a silicon-on-insulated conductor structure for semiconductor integrated circuits, comprising the steps of: providing a substrate of semiconductor material of a first conductivity type having a substantially smooth and trenchless first side and a second side; depositing a first layer of semiconducting material of a second conductivity type directly on all of said first side of said substrate; defining a plurality of islands in said first layer; growing a second layer of said semiconducting material on at least one of said islands, said second layer being of said first conductivity type; forming a porous region beneath said at least one island; and selectively oxidizing said porous region to form an isolating layer.
Claim 3
Independent Claim
143 words
A method of fabricating a silicon-on-insulated conductor structure for semiconductor integrated circuits, comprising the steps of: providing a substrate of semiconductor material of a first conductivity type having a substantially smooth and trenchless first side and a second side; depositing a first layer of semiconducting material of a second conductivity type directly on all of said first side of said substrate; defining a plurality of islands in said first layer; growing a second layer of said semiconductor material on at least one of said islands, said second layer being of said first conductivity type; forming a first porous region beneath said at least one island and a second porous region beneath another one of said islands; selectively oxidizing said first and second porous regions; and defining a semiconductor device in each of said at least one of said islands and said second layer.
Claim 4
Independent Claim
143 words
A method of fabricating a silicon-on-insulated conductor structure for semiconductor integrated circuits, comprising the steps of: providing a substrate of semiconductor material of a first conductivity type having a substantially smooth and trenchless first side and a second side; depositing a first layer of semiconducting material of a second conductivity type directly on all of said first side of said substrate; defining a plurality of islands in said first layer; growing a second layer of said semiconductor material on at least one of said islands, said second layer being of said first conductivity type; forming a first porous region beneath said at least one island and a second porous region beneath another one of said islands; selectively oxidizing said first and second porous regions; and defining a semiconductor device in each of said at least one of said islands and said second layer.
Claim 5
Dependent Claim
13 words
The method of claim 2, wherein said semiconductor material is single crystal silicon.
Claim 6
Dependent Claim
21 words
The method of claim 2, wherein said semiconductor device is selected from the group consisting of diodes, transistors, resistors, and capacitors.
Claim 7
Dependent Claim
59 words
The method of claim 2, wherein said semiconductor device has at least two terminals comprised of semiconductor material of said second conductivity, said terminals comprising the source and drain terminals of a transistor and wherein said semiconductor device further comprises a channel between said source and drain terminals, said channel being comprised of semiconductor material of said first conductivity.
Claim 8
Dependent Claim
13 words
The method according to claim 2, wherein said first conductivity type is n-type.
Claim 9
Dependent Claim
15 words
The method of claim 1, further comprising forming a semiconductor device in said second layer.
Claim 10
Dependent Claim
26 words
The method of claim 7, wherein said device forming step comprises implanting at least one heavily doped region having said second conductivity into said second layer.
Claim 11
Dependent Claim
44 words
The method of claim 1, further comprising a step of forming a second porous region in said substrate beneath another one of said islands and oxidizing said second region to form an isolating layer between said substrate and said another one of said islands.
Claim 12
Dependent Claim
21 words
The method of claim 9, further comprising the step of forming a semiconductor device in said another one of said islands.
Claim 13
Dependent Claim
39 words
The method of claim 10, wherein said step of forming a semiconductor device in said another one of said islands comprises implanting at least one heavily doped region having said second conductivity into said another one of said islands.
Claim 14
Dependent Claim
18 words
The method of claim 2, wherein said step of forming a porous region includes electrochemically anodizing said substrate.
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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) | 2000-01-28 | 2000-07-29 | 2001-01-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-01-28 | 2004-07-29 | 2005-01-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-01-28 | 2008-07-29 | 2009-01-28 | $7700.00 | Window Closed / Lapsed |