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US5378659A
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Method and structure for forming an integrated circuit pattern on a semiconductor substrate
Assignee: NXP USA Inc
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Filing: 1993-07-06
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Granted: 1995-01-03
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Expires: 2013-07-06
Abstract
Abstract Reflective notching of a photoresist pattern (20), generated over reflective materials on a semiconductor substrate (12), is minimized by using an anti-reflective layer (20) of silicon-rich silicon nitride. The layer of silicon-rich silicon nitride is formed over the reflective materials and a layer of photoresist is then formed over the silicon-rich silicon nitride. The photoresist layer is then photolithographically patterned to form an integrated circuit pattern (20). The silicon-rich silicon nitride layer has an absorptive index of greater than 0.25, which allows it to be used as an anti-reflective layer with photolithographic patterning systems having ultraviolet and deep ultraviolet exposure wavelengths.
Inventors
- 👤 Bernard J. Roman
- 👤 Bich-Yen Nguyen
- 👤 Chandrasekaram Ramiah
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 08:55
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/70; G03F7/70483; G03F7/7055; G03F7/70583; G03F7/004; G03F7/09; G03F7/091; G03F7/70425; G03F7/70433; G03F7/70441; G03F7/70691; H; H10; H10P; H10P76/00; H10P76/20; H10P76/204; H10P76/2041; H10P76/2043; Y; Y10; Y10S; Y10S438/00; Y10S438/942; Y10S438/948; Y10S438/952
Claims Analysis
Total Claims: 37
Claim 1
Independent Claim
113 words
A method for forming an integrated circuit pattern on a semiconductor substrate comprising the steps of: providing the semiconductor substrate, the semiconductor substrate having a major surface; forming a device layer overlying the major surface of the semiconductor substrate; forming an anti-reflective layer having an absorptive index overlying the device layer, wherein the anti-reflective layer is an inorganic dielectric material containing silicon and nitrogen; forming a photoresist layer overlying the anti-reflective layer; and exposing a portion of the photoresist layer to electromagnetic radiation to form the integrated circuit pattern, wherein the electromagnetic radiation has an exposure wavelength and the absorptive index of the anti-reflective layer is greater than 0.05 at the exposure wavelength.
Claim 2
Independent Claim
113 words
A method for forming an integrated circuit pattern on a semiconductor substrate comprising the steps of: providing the semiconductor substrate, the semiconductor substrate having a major surface; forming a device layer overlying the major surface of the semiconductor substrate; forming an anti-reflective layer having an absorptive index overlying the device layer, wherein the anti-reflective layer is an inorganic dielectric material containing silicon and nitrogen; forming a photoresist layer overlying the anti-reflective layer; and exposing a portion of the photoresist layer to electromagnetic radiation to form the integrated circuit pattern, wherein the electromagnetic radiation has an exposure wavelength and the absorptive index of the anti-reflective layer is greater than 0.05 at the exposure wavelength.
Claim 3
Dependent Claim
21 words
The method of claim 1, wherein the step of forming the anti-reflective layer comprises: forming a layer of silicon-rich silicon nitride.
Claim 4
Dependent Claim
28 words
The method of claim 2, wherein the step of forming the layer of silicon-rich silicon nitride comprises: forming the layer of silicon-rich silicon nitride by chemical vapor deposition.
Claim 5
Dependent Claim
25 words
The method of claim 1, wherein the step of forming the anti-reflective layer comprises: forming the anti-reflective layer with a thickness greater than 5 nanometers.
Claim 6
Dependent Claim
21 words
The method of claim 1, wherein the step of forming the anti-reflective layer comprises: depositing the anti-reflective layer using a plasma.
Claim 7
Dependent Claim
19 words
The method of claim 5, wherein the step of forming the device layer comprises: forming a layer containing aluminum.
Claim 8
Dependent Claim
22 words
The method of claim 1, wherein the step of forming the anti-reflective layer comprises: forming the anti-reflective layer by chemical vapor deposition.
Claim 9
Dependent Claim
18 words
The method of claim 1, wherein the step of forming the device layer comprises: forming a conductive layer.
Claim 10
Dependent Claim
26 words
The method of claim 8, wherein the step of forming the conductive layer comprises: forming a composite layer comprising a silicide layer overlying a polysilicon layer.
Claim 11
Dependent Claim
19 words
The method of claim 8, wherein the step of forming the conductive layer comprises: forming a layer of polysilicon.
Claim 12
Dependent Claim
18 words
The method of claim 1, wherein the step of exposing the exposure wavelength is less than 440 nanometers.
Claim 13
Dependent Claim
62 words
The method of claim 11, wherein the step of forming the anti-reflective layer comprises: forming the anti-reflective layer having a refractive index and a thickness, wherein the thickness is approximated by the equation t=λ/4n, where t is the thickness of the anti-reflective layer, λ is the exposure wavelength of the electromagnetic radiation, and n is the refractive index of the anti-reflective layer.
Claim 14
Dependent Claim
25 words
The method of claim 11, wherein the step of exposing the absorptive index of the anti-reflective layer is greater than 0.25 at the exposure wavelength.
Claim 15
Dependent Claim
16 words
The method of claim 1, wherein the step of exposing the exposure wavelength is 248 nanometers.
Claim 16
Dependent Claim
27 words
The method of claim 1 further comprising the step of: forming an insulating layer, wherein the insulating layer overlies the anti-reflective layer and underlies the photoresist layer.
Claim 17
Dependent Claim
27 words
The method of claim 1 further comprising the step of: forming an insulating layer, wherein the insulating layer overlies the device layer and underlies the anti-reflective layer.
Claim 18
Independent Claim
110 words
A method for forming an integrated circuit pattern on a semiconductor substrate comprising the steps of: providing the semiconductor substrate, the semiconductor substrate having a major surface; forming a device layer overlying the major surface of the semiconductor substrate; forming an anti-reflective layer of silicon-rich silicon nitride overlying the device layer, the anti-reflective layer having an absorptive index; forming a photoresist layer overlying the layer of silicon-rich silicon nitride; and exposing a portion of the photoresist layer to electromagnetic radiation to form the integrated circuit pattern, wherein the electromagnetic radiation has an exposure wavelength and the absorptive index of the anti-reflective layer is greater than 0.05 at the exposure wavelength.
Claim 19
Independent Claim
110 words
A method for forming an integrated circuit pattern on a semiconductor substrate comprising the steps of: providing the semiconductor substrate, the semiconductor substrate having a major surface; forming a device layer overlying the major surface of the semiconductor substrate; forming an anti-reflective layer of silicon-rich silicon nitride overlying the device layer, the anti-reflective layer having an absorptive index; forming a photoresist layer overlying the layer of silicon-rich silicon nitride; and exposing a portion of the photoresist layer to electromagnetic radiation to form the integrated circuit pattern, wherein the electromagnetic radiation has an exposure wavelength and the absorptive index of the anti-reflective layer is greater than 0.05 at the exposure wavelength.
Claim 20
Dependent Claim
18 words
The method of claim 17, wherein the step of forming the device layer comprises: forming a conductive layer.
Claim 21
Dependent Claim
19 words
The method of claim 18, wherein the step of forming the conductive layer comprises: forming a layer containing aluminum.
Claim 22
Dependent Claim
26 words
The method of claim 18, wherein the step of forming the conductive layer comprises: forming a composite layer comprising a silicide layer overlying a polysilicon layer.
Claim 23
Dependent Claim
19 words
The method of claim 18, wherein the step of forming the conductive layer comprises: forming a layer of polysilicon.
Claim 24
Dependent Claim
18 words
The method of claim 17, wherein the step of exposing the exposure wavelength is less than 440 nanometers.
Claim 25
Dependent Claim
62 words
The method of claim 22, wherein the step of forming the anti-reflective layer comprises: forming the anti-reflective layer having a refractive index and a thickness, wherein the thickness is approximated by the equation t=λ/4n, where t is the thickness of the anti-reflective layer, λ is the exposure wavelength of the electromagnetic radiation, and n is the refractive index of the anti-reflective layer.
Claim 26
Dependent Claim
25 words
The method of claim 22, wherein the step of exposing the absorptive index of the anti-reflective layer is greater than 0.25 at the exposure wavelength.
Claim 27
Dependent Claim
16 words
The method of claim 17, wherein the step of exposing the exposure wavelength is 248 nanometers.
Claim 28
Dependent Claim
25 words
The method of claim 17, wherein the step of forming the anti-reflective layer comprises: forming the anti-reflective layer with a thickness greater than 5 nanometers.
Claim 29
Independent Claim
107 words
A method for forming an integrated circuit pattern on a semiconductor substrate comprising the steps of: providing the semiconductor substrate, the semiconductor substrate having a major surface; forming a polysilicon layer overlying the major surface of the semiconductor substrate; forming an anti-reflective layer of silicon-rich silicon nitride overlying the polysilicon layer, the anti-reflective layer having an absorptive index; forming a photoresist layer overlying the anti-reflective layer; and exposing a portion of the photoresist layer to electromagnetic radiation to form the integrated circuit pattern, wherein the electromagnetic radiation has an exposure wavelength and the absorptive index of the anti-reflective layer is greater than 0.05 at the exposure wavelength.
Claim 30
Independent Claim
107 words
A method for forming an integrated circuit pattern on a semiconductor substrate comprising the steps of: providing the semiconductor substrate, the semiconductor substrate having a major surface; forming a polysilicon layer overlying the major surface of the semiconductor substrate; forming an anti-reflective layer of silicon-rich silicon nitride overlying the polysilicon layer, the anti-reflective layer having an absorptive index; forming a photoresist layer overlying the anti-reflective layer; and exposing a portion of the photoresist layer to electromagnetic radiation to form the integrated circuit pattern, wherein the electromagnetic radiation has an exposure wavelength and the absorptive index of the anti-reflective layer is greater than 0.05 at the exposure wavelength.
Claim 31
Dependent Claim
22 words
The method of claim 27, wherein the step of forming the anti-reflective layer comprises: forming the anti-reflective layer by chemical vapor deposition.
Claim 32
Dependent Claim
18 words
The method of claim 27, wherein the step of exposing the exposure wavelength is less than 440 nanometers.
Claim 33
Dependent Claim
62 words
The method of claim 29, wherein the step of forming the anti-reflective layer comprises: forming the anti-reflective layer having a refractive index and a thickness, wherein the thickness is approximated by the equation t=λ/4n, where t is the thickness of the anti-reflective layer, λ is the exposure wavelength of the electromagnetic radiation, and n is the refractive index of the anti-reflective layer.
Claim 34
Dependent Claim
25 words
The method of claim 29, wherein the step of exposing the absorptive index of the anti-reflective layer is greater than 0.25 at the exposure wavelength.
Claim 35
Dependent Claim
16 words
The method of claim 27, wherein the step of exposing the exposure wavelength is 248 nanometers.
Claim 36
Dependent Claim
27 words
The method of claim 27 further comprising the step of: forming an insulating layer, wherein the insulating layer overlies the anti-reflective layer and underlies the photoresist layer.
Claim 37
Dependent Claim
25 words
The method of claim 27, wherein the step of forming the anti-reflective layer comprises: forming the anti-reflective layer with a thickness greater than 5 nanometers.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-01-02 | 1998-07-04 | 1999-01-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-01-02 | 2002-07-04 | 2003-01-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-01-02 | 2006-07-04 | 2007-01-03 | $7700.00 | Window Closed / Lapsed |