US5066615A
Expired / Lapsed
US
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Photolithographic processes using thin coatings of refractory metal silicon nitrides as antireflection layers
Assignee: Nokia Bell Labs
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Filing: 1990-08-06
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Granted: 1991-11-19
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Expires: 2010-08-06
Abstract
Abstract An antireflection coating (21) for use in integrated circuit processing consists of a film of x-silicon-nitride, where x is a metal from the group consisting of titanium, vanadium, chromium, zirconium, niobium, molybdenum, hafnium, tantalum and tungsten. These coatings are preferably made by sputtering, with the x silicon nitride coating being made by sputtering in a nitrogen-containing atmosphere.
Inventors
- 👤 Michael F. Brady
- 👤 II John K. Dorey
- 👤 Aubrey L. Helms, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 02:57
CPC Classifications
H; H10; H10P; H10P76/00; H10P76/20; H10P76/204; H10P76/2041; H10P76/2043; G; G03; G03F; G03F7/00; G03F7/004; G03F7/09; G03F7/091; Y; Y10; Y10S; Y10S148/00; Y10S148/137; Y10S148/147; Y10S438/00; Y10S438/942; Y10S438/948; Y10S438/952
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
109 words
A photolithographic method for making a pattern over a reflective surface comprising the steps of: covering a reflective surface of a substrate with an antireflection coating; covering the antireflection coating with a radiation-sensitive material; selectively exposing the radiation-sensitive material to electromagnetic radiation by directing electromagnetic radiation through a patterned mask onto selected regions of the radiation-sensitive material to form a pattern; selectively removing the radiation-sensitive material in accordance with said pattern, thereby to form a patterned mask, characterized in that: the antireflection coating is a composition containing x-silicon-nitride, where x is a metal taken from the group consisting of titanium, vanadium, chromium, zirconium, niobium, molybdenum, hafnium, tantalum and tungsten.
Claim 2
Dependent Claim
109 words
A photolithographic method for making a pattern over a reflective surface comprising the steps of: covering a reflective surface of a substrate with an antireflection coating; covering the antireflection coating with a radiation-sensitive material; selectively exposing the radiation-sensitive material to electromagnetic radiation by directing electromagnetic radiation through a patterned mask onto selected regions of the radiation-sensitive material to form a pattern; selectively removing the radiation-sensitive material in accordance with said pattern, thereby to form a patterned mask, characterized in that: the antireflection coating is a composition containing x-silicon-nitride, where x is a metal taken from the group consisting of titanium, vanadium, chromium, zirconium, niobium, molybdenum, hafnium, tantalum and tungsten.
Claim 3
Dependent Claim
16 words
The method of claim 1 further characterized in that: the antireflection coating is made by sputtering.
Claim 4
Dependent Claim
20 words
The method of claim 2 further characterized in that: the reflective surface of the substrate comprises a coating of aluminum.
Claim 5
Dependent Claim
24 words
The method of claim 3 further characterized in that: the mask is used as a pattern for selectively etching the aluminum and antireflection coatings.
Claim 6
Dependent Claim
30 words
The method of claim 4 further characterized in that: the sputtering is done in an atmosphere containing nitrogen and the antireflection coating is a composition containing tungsten, silicon and nitrogen.
Claim 7
Dependent Claim
17 words
The method of claim 1 further characterized in that: the antireflection coating is a composition containing tungsten-silicon-nitride.
Claim 8
Dependent Claim
17 words
The method of claim 1 further characterized in that: the antireflection coating is a composition containing titanium-silicon-nitride.
Claim 9
Dependent Claim
17 words
The method of claim 1 further characterized in that: the antireflection coating is a composition containing tantalum-silicon-nitride.
Claim 10
Dependent Claim
31 words
The method of claim 2 further characterized in that: the sputtering step uses a single target comprising tungsten and silicon; and the antireflection coating has a thickness of 125-750 angstrom units.
Claim 11
Dependent Claim
41 words
The method of claim 2 further characterized in that: the sputtering step uses two targets, one comprising silicon and the other target comprising a metal taken from the group consisting of tatanium, vanadium, chromium, zirconium, niobium, molybdenum, hafnium, tantalum and tungsten.
Claim 12
Independent Claim
146 words
A method for making an integrated circuit comprising the steps of: forming over a semiconductor layer a dielectric layer; forming over the dielectric layer a metal layer; forming over the metal layer an antireflection coating of x-silicon-nitride, where x is a metal taken from the group consisting of titanium, vanadium, chromium, zirconium, niobium, molybdenum, hafnium, tantalum and tungsten; covering the antireflection coating with a layer of photoresist material; selectively exposing the photoresist material to light by directing light through a patterned mask onto selected regions of the photoresist material to form a pattern; selectively removing the photoresist material in accordance with said pattern thereby to form a patterned mask of the remaining photoresist material; and using the patterned mask to selectively etch exposed regions of the antireflection coating and the metal layer, thereby to form a conductive pattern of the metal layer overlying the dielectric layer.
Claim 13
Independent Claim
146 words
A method for making an integrated circuit comprising the steps of: forming over a semiconductor layer a dielectric layer; forming over the dielectric layer a metal layer; forming over the metal layer an antireflection coating of x-silicon-nitride, where x is a metal taken from the group consisting of titanium, vanadium, chromium, zirconium, niobium, molybdenum, hafnium, tantalum and tungsten; covering the antireflection coating with a layer of photoresist material; selectively exposing the photoresist material to light by directing light through a patterned mask onto selected regions of the photoresist material to form a pattern; selectively removing the photoresist material in accordance with said pattern thereby to form a patterned mask of the remaining photoresist material; and using the patterned mask to selectively etch exposed regions of the antireflection coating and the metal layer, thereby to form a conductive pattern of the metal layer overlying the dielectric layer.
Claim 14
Dependent Claim
88 words
The method of claim 11 wherein: the antireflection layer is made by first locating the metal layer in a sputtering reactor having targets of silicon and of the material x; establishing between the metal layer and the target a low-pressure atmosphere including nitrogen; ionizing the atmosphere with sufficient energy to create a plasma between the metal layer and the target and to cause particles to be sputtered from the targets onto the metal layer through the plasma so as to create the x-silicon-nitride coating on the metal layer.
Claim 15
Dependent Claim
12 words
The method of claim 12 wherein: the metal layer consists of aluminum.
Claim 16
Dependent Claim
15 words
The method of claim 13 wherein: the antireflection coating has thickness of 125-750 angstrom units.
Claim 17
Dependent Claim
12 words
The method of claim 14 wherein: the x-silicon-nitride has the formula TiSiN.
Claim 18
Dependent Claim
12 words
The method of claim 14 wherein: the x-silicon-nitride has the formula TaSiN.
Claim 19
Independent Claim
125 words
A method for making an integrated circuit comprising the steps of: forming over a semiconductor layer a dielectric layer; forming over the dielectric layer a metal layer; forming over the metal layer an antireflection coating of tungsten-silicon-nitride; covering the antireflection coating with a layer of photoresist material; selectively exposing the photoresist material to light by directing light through a patterned mask onto selected regions of the photoresist material to form a pattern; selectively removing the photoresist material in accordance with said pattern, thereby to form a patterned mask of the remaining photoresist material; and using the patterned mask to selectively etch exposed regions of the antireflection coating and the metal layer, thereby to form a conductive pattern of the metal layer overlying the dielectric layer.
Claim 20
Independent Claim
125 words
A method for making an integrated circuit comprising the steps of: forming over a semiconductor layer a dielectric layer; forming over the dielectric layer a metal layer; forming over the metal layer an antireflection coating of tungsten-silicon-nitride; covering the antireflection coating with a layer of photoresist material; selectively exposing the photoresist material to light by directing light through a patterned mask onto selected regions of the photoresist material to form a pattern; selectively removing the photoresist material in accordance with said pattern, thereby to form a patterned mask of the remaining photoresist material; and using the patterned mask to selectively etch exposed regions of the antireflection coating and the metal layer, thereby to form a conductive pattern of the metal layer overlying the dielectric layer.
Claim 21
Dependent Claim
86 words
The method of claim 17 wherein: the antireflection layer is made by first locating the metal layer in a sputtering reactor having a target of tungsten and silicon; establishing between the metal layer and the target a low-pressure atmosphere including nitrogen; ionizing the atmosphere with sufficient energy to create a plasma between the metal layer and the target and to cause particles to be sputtered from the target onto the metal layer through the plasma so as to create a tungsten-silicon-nitride coating on the metal layer.
Claim 22
Dependent Claim
12 words
The method of claim 18 wherein: the metal layer consists of aluminum.
Claim 23
Dependent Claim
16 words
The method of claim 19 wherein: the antireflection coating has a thickness of 125-750 angstrom units.
Claim 24
Dependent Claim
12 words
The method of claim 18 wherein: the tungsten-silicon-nitride has the formula WSiN.
References Cited (Backward Citations)
US4510178A
Cited
US4398341A
Cited
US4640001A
Cited
US4760369A
Cited
JPS6289355A
Cited
US4820611A
Cited
JPS63287001A
Cited
US4981550A
Cited
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