US5668028A
Expired / Lapsed
US
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Method of depositing thin nitride layer on gate oxide dielectric
Assignee: STMicroelectronics lnc USA
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Filing: 1995-04-28
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Granted: 1997-09-16
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Expires: 2015-04-28
Abstract
Abstract A gate structure in a transistor and method for fabricating the structure. A gate structure is formed on a substrate. The gate structure includes three layers: an oxide layer, a nitride layer and a polysilicon layer. The oxide layer is located on the substrate, the nitride layer is located on the oxide layer, and the polysilicon layer is located on the nitride layer. The gate structure is reoxidized to form a layer of oxide over the gate structure.
Inventors
- 👤 Frank Randolph Bryant
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 15:11
CPC Classifications
H; H10; H10D; H10D64/00; H10D64/01; H10D64/013; H10D64/01302; H10D64/01332; H10D64/01336; H10D64/0134; H10D30/00; H10D30/01; H10D30/021; H10D30/0223; H10D30/0227; H10D64/01338; H10D64/01344; H10D64/021; H10D64/60; H10D64/66; H10D64/68; H10D64/681; H10D64/685; H10D64/693; H10D30/60; H10D30/601; H10D64/691; Y; Y10; Y10S; Y10S257/00; Y10S257/90
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
93 words
A method for fabricating a portion of a semiconductor device comprising: forming a gate oxide layer on and in contact with a surface of a substrate, wherein the gate oxide layer is less than 200 Å thick; forming a nitride layer on the oxide gate layer; forming a polysilicon layer on the nitride layer; etching away the polysilicon and nitride layers in areas to form a gate structure; and reoxidizing the gate structure to form a layer of oxide, wherein a formation of asperities on an underside of the polysilicon layer is prevented.
Claim 2
Independent Claim
93 words
A method for fabricating a portion of a semiconductor device comprising: forming a gate oxide layer on and in contact with a surface of a substrate, wherein the gate oxide layer is less than 200 Å thick; forming a nitride layer on the oxide gate layer; forming a polysilicon layer on the nitride layer; etching away the polysilicon and nitride layers in areas to form a gate structure; and reoxidizing the gate structure to form a layer of oxide, wherein a formation of asperities on an underside of the polysilicon layer is prevented.
Claim 3
Dependent Claim
23 words
The method of claim 1, wherein the step of forming a nitride layer comprises depositing a nitride layer on the gate oxide layer.
Claim 4
Dependent Claim
34 words
The method of claim 1, wherein the step of forming a nitride layer includes depositing the nitride layer on the gate oxide layer to a thickness from about 10 Å to about 50 Å.
Claim 5
Dependent Claim
39 words
The method of claim 1, wherein the step of etching exposes the surface of the substrate; and wherein the step of reoxidizing the gate structure comprises exposing the substrate to an oxidizing ambient to oxidize the exposed substrate surface.
Claim 6
Dependent Claim
28 words
The method of claim 4, wherein the exposing step includes exposing the substrate to the oxidizing ambient at a temperature from about 650° C. to about 900° C.
Claim 7
Dependent Claim
26 words
The method of claim 5, wherein the exposing step further includes exposing the substrate to the oxidizing ambient for about 10 minutes to abut 60 minutes.
Claim 8
Dependent Claim
19 words
The method of claim 1, wherein prior to the reoxidizing step, forming source and drain regions in the substrate.
Claim 9
Dependent Claim
19 words
The method of claim 1, further comprising forming source and drain regions in the substrate after the reoxidizing step.
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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) | 2000-09-15 | 2001-03-17 | 2001-09-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-09-15 | 2005-03-17 | 2005-09-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-09-15 | 2009-03-17 | 2009-09-16 | $7700.00 | Window Closed / Lapsed |