Patent US5851927A successfully refreshed from Google Patents.
US5851927A
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Method of forming a semiconductor device by DUV resist patterning
Assignee: North Star Innovations Inc
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Filing: 1997-08-29
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Granted: 1998-12-22
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Expires: 2017-08-29
Abstract
Abstract A method for forming a semiconductor device, including providing a silicon substrate (10), forming a gate stack (11) on the substrate (10), coating a deep ultra-violet (DUV) photoresist (30) on the gate stack (11), exposing and developing the photoresist (30), and etching the gate stack (11). According to the present invention, the gate stack (11) has a dielectric nitride layer (26), particularly, a silicon nitride layer. An adhesive oxide layer (28) is provided between the nitride layer (26) and the photoresist (30) to prevent undesirable lifting of the photoresist (30). Yield is greatly increased and defectivity is reduced.
Inventors
- 👤 Paul Kevin Cox
- 👤 Thy Ngu-Uyen Tran
- 👤 Samuel Jay Wright
- 👤 Judith Sobresky
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 03:30
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/01; H10D30/021; H10D30/0223; H10D30/0227; H10D64/00; H10D64/01; H10D64/013; H10D64/01302; H10D64/01304; H10D64/01326; H10D64/01354; H10D64/021; H10P; H10P76/00; H10P76/20; H10P76/204; H10P76/2041; H10P76/2043
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
96 words
A method of forming a semiconductor device comprising the steps of: providing a silicon substrate; forming a gate stack on the silicon substrate comprising the steps of: forming a gate electrode on the silicon substrate; forming a silicon nitride layer on the gate electrode; and forming an adhesive oxide layer on the silicon nitride layer; forming a DUV photoresist on the gate stack; exposing the DUV photoresist to DUV energy and developing the DUV photoresist to remove portions thereof to leave exposed regions of the gate stack; and etching the exposed regions of the gate stack.
Claim 2
Independent Claim
96 words
A method of forming a semiconductor device comprising the steps of: providing a silicon substrate; forming a gate stack on the silicon substrate comprising the steps of: forming a gate electrode on the silicon substrate; forming a silicon nitride layer on the gate electrode; and forming an adhesive oxide layer on the silicon nitride layer; forming a DUV photoresist on the gate stack; exposing the DUV photoresist to DUV energy and developing the DUV photoresist to remove portions thereof to leave exposed regions of the gate stack; and etching the exposed regions of the gate stack.
Claim 3
Dependent Claim
16 words
The method of claim 1, wherein the gate electrode comprises at least one polycrystalline silicon layer.
Claim 4
Dependent Claim
20 words
The method of claim 2, wherein the at least one polycrystalline silicon layer comprises first and second polycrystalline silicon layers.
Claim 5
Dependent Claim
18 words
The method of claim 1, further comprising the step of depositing an antireflective coating on the gate electrode.
Claim 6
Dependent Claim
13 words
The method of claim 4, wherein the antireflective coating comprises silicon-rich silicon nitride.
Claim 7
Dependent Claim
26 words
The method of claim 1, further comprising the step of depositing a gate oxide layer overlying the silicon substrate, on which the gate stack is provided.
Claim 8
Dependent Claim
27 words
The method of claim 6, wherein the gate electrode is formed by providing a polycrystalline silicon layer and depositing a metal-containing layer on the polycrystalline silicon layer.
Claim 9
Dependent Claim
12 words
The method of claim 7, wherein the metal-containing layer comprises tungsten silicide.
Claim 10
Dependent Claim
12 words
The method of claim 7, wherein the metal-containing layer comprises titanium silicide.
Claim 11
Dependent Claim
13 words
The method of claim 1, wherein the adhesive oxide layer comprises silicon dioxide.
Claim 12
Dependent Claim
14 words
The method of claim 10, wherein the silicon dioxide is formed by decomposing TEOS.
Claim 13
Dependent Claim
14 words
The method of claim 1, wherein the silicon nitride layer comprises stoichiometric silicon nitride.
Claim 14
Dependent Claim
20 words
The method of claim 1, wherein the adhesive oxide layer has a thickness within a range of about 30-150 angstroms.
Claim 15
Dependent Claim
20 words
The method of claim 13, wherein the adhesive oxide layer has a thickness within a range of about 30-100 angstroms.
Claim 16
Dependent Claim
20 words
The method of claim 14, wherein the adhesive oxide layer has a thickness within a range of about 50-75 angstroms.
Claim 17
Independent Claim
74 words
A method for etching a material comprising the steps of: forming an adhesive oxide layer on the material having a nitride surface, such that the adhesive oxide layer covers the nitride surface; forming a DUV photoresist on the adhesive oxide layer; exposing portions of the DUV photoresist; developing the DUV photoresist to remove the portions of the DUV photoresist and leave exposed regions of the material; and etching the exposed regions of the material.
Claim 18
Independent Claim
74 words
A method for etching a material comprising the steps of: forming an adhesive oxide layer on the material having a nitride surface, such that the adhesive oxide layer covers the nitride surface; forming a DUV photoresist on the adhesive oxide layer; exposing portions of the DUV photoresist; developing the DUV photoresist to remove the portions of the DUV photoresist and leave exposed regions of the material; and etching the exposed regions of the material.
Claim 19
Dependent Claim
11 words
The method of claim 16, wherein the material comprises a nitride.
Claim 20
Dependent Claim
11 words
The method of claim 17, wherein the material comprises silicon nitride.
Claim 21
Dependent Claim
11 words
The method of claim 16, wherein the material comprises polycrystalline silicon.
Claim 22
Dependent Claim
17 words
The method of claim 19, wherein the nitride surface is a skin layer on the polycrystalline silicon.
Claim 23
Dependent Claim
12 words
The method of claim 20, wherein the nitride surface comprises titanium nitride.
Claim 24
Dependent Claim
13 words
The method of claim 16, wherein the adhesive oxide layer comprises silicon dioxide.
Claim 25
Dependent Claim
14 words
The method of claim 22, wherein the silicon dioxide is formed by decomposing TEOS.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 2001-12-21 | 2002-06-22 | 2002-12-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-12-21 | 2006-06-22 | 2006-12-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-12-21 | 2010-06-22 | 2010-12-22 | $7700.00 | Window Closed / Lapsed |