Patent EP0520216A2 successfully refreshed from Google Patents.
EP0520216A2
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EP
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Fabrication of defect free silicon on an insulating substrate
Assignee: International Business Machines Corp
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Filing: 1992-06-03
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Granted: —
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Expires: 2012-06-03
Abstract
Abstract A method for fabricating silicon on insulator structures having a dislocation free silicon layer. The method utilizes low temperature UHVCVD to deposit a very heavily doped etch stop layer (12) having a very steep doping profile onto a substrate (10) and a lightly doped active layer (14) onto the etch stop layer. An insulator (16) is formed on the active layer and a carrier wafer (18) is formed on the insulator layer. The original substrate is removed in a first etch and the etch stop layer is removed in a second etch resulting in a thin, uniform active layer. In one embodiment, a small percentage of germanium is added to the etch stop layer to produce a defect free epitaxial active layer.
Inventors
- 👤 Robert H. Dennard
- 👤 Bernard S Meyerson
- 👤 Robert Rosenberg
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 13:39
CPC Classifications
H; H10; H10P; H10P90/00; H10P90/19; H10P90/1904; H10P90/1906; H10P90/1914; H10W; H10W10/00; H10W10/10; H10W10/181; Y; Y10; Y10S; Y10S148/00; Y10S148/012; Y10S148/135; Y10S438/00; Y10S438/97; Y10S438/977
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
72 words
Method of forming a silicon on insulator structure comprising the steps of: forming an etch stop layer (12) of very heavily doped silicon on a silicon substrate (10); forming an active layer (14) of lightly doped silicon on said etch stop layer; forming an insulator layer (16) on said active layer; forming a carrier substrate (18) on said insulator layer; removing said silicon substrate (10); and removing said etch stop layer (12).
Claim 2
Dependent Claim
17 words
The method of claim 1 wherein said etch stop layer is formed with a steep doping profile.
Claim 3
Independent Claim
25 words
The method of claims 1 or 2 wherein said etch stop layer is formed with a doping concentration level of about 10²¹ cm⁻³ or greater.
Claim 4
Independent Claim
28 words
The method of anyone of claims 1 to 3 wherein said etch stop layer and said active layer are formed by epitaxially growing silicon or SiGe by UHVCVD.
Claim 5
Independent Claim
23 words
The method of anyone of claims 1 to 4 wherein said etch stop layer and said active layer include about 2 percent germanium.
Claim 6
Independent Claim
18 words
The method of anyone of the preceding claims wherein said active layer is a compound semi-conductor of SiGe.
Claim 7
Independent Claim
22 words
The method of anyone of the preceding claims wherein said insulator layer is one of a silicon oxide and a silicon nitride.
Claim 8
Dependent Claim
22 words
The method of claim 7 wherein said insulator layer is formed by depositing an insulator material by PECVD, or by thermal oxidation.
Claim 9
Independent Claim
26 words
The method of anyone of the preceding claims wherein said carrier substrate is comprised of polysilicon and said forming step includes depositing said polysilicon by PECVD.
Claim 10
Dependent Claim
26 words
The method of claim 9 wherein said step of forming a carrier substrate on said insulator layer includes bonding a carrier wafer to said insulator layer.
Claim 11
Independent Claim
60 words
The method of anyone of the preceding claims wherein said bonding step includes forming a layer of polysilicon on said insulator layer, forming a layer of germanium on said polysilicon layer, forming a layer of germanium on a silicon wafer, contracting the germanium layers and exposing said layers to temperatures sufficient to bond the carrier substrate to said insulator layer.
Claim 12
Dependent Claim
14 words
The method of claim 10 wherein said carrier wafer is a glass ceramic material.
Claim 13
Dependent Claim
43 words
The method of claim 12 wherein said bonding step includes forming a layer of SiO₂ on said carrier wafer and said insulator layer, contacting the SiO₂ layers and exposing said layers to temperatures sufficient to bond the carrier substrate to said insulator layer.
Claim 14
Dependent Claim
43 words
The method of claim 9 wherein said bonding step includes forming a layer of sol-gel on said carrier substrate and said insulator layer, contacting the sol-gel layers and exposing said layers to temperatures sufficient to bond the carrier substrate to said insulator layer.
Claim 15
Dependent Claim
46 words
A silicon on insulator structure according to anyone of claims 1 to 14 comprising: a substrate; an insulator layer formed on said substrate; and an active layer of silicon formed on said insulator layer, said active layer being substantially dislocation free and of substantially uniform thickness.
Claim 16
Dependent Claim
16 words
The structure of claim 15 wherein the dislocation level of said active layer is ≦ 10⁻².
Claim 17
Dependent Claim
14 words
The structure of claims 15 or 16 wherein the thickness uniformity is ± 5%.
Claim 18
Dependent Claim
15 words
The structure of claims 15 to 17 wherein said substrate comprises a glass ceramic material.
Claim 19
Dependent Claim
31 words
The structure of claim 18 wherein said glass ceramic material has an expansion coefficient approximately equal to silicon, said glass ceramic preferably selected from the group consisting of cordierite and muellite.
References Cited (Backward Citations)
No citation records indexed.
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