US5525542A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for making a semiconductor device having anti-reflective coating
Assignee: NXP USA Inc
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Filing: 1995-02-24
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Granted: 1996-06-11
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Expires: 2015-02-24
Abstract
Abstract An anti-reflective coating (ARC) (20) is formed over a reflective, conductive layer (18), such as polysilicon or aluminum, in a semiconductor device (10). The ARC is an aluminum nitride layer. During photolithography, the ARC absorbs radiation waves (30), particularly absorbing wavelengths under 300 nanometers, such as deep ultraviolet (DUV) radiation at 248 nanometers. Being absorbed by the ARC, the radiation waves are prevented from reflecting off the underlying conductive layer. Thus, resist mask (34) is patterned and developed true to the pattern on lithography mask (24), resulting in accurate replication into appropriate layers of the device.
Inventors
- 👤 Papu D. Maniar
- 👤 Robert W. Fiordalice
- 👤 Kevin G. Kemp
- 👤 Bernard J. Roman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 22:25
CPC Classifications
H; H10; H10P; H10P76/00; H10P76/20; H10P76/204; H10P76/2041; H10P76/2043; Y; Y10; Y10S; Y10S148/00; Y10S148/113; Y10S438/00; Y10S438/942; Y10S438/948; Y10S438/952
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
106 words
A method for making a semiconductor device, comprising the steps of: providing a semiconductor substrate; depositing a conductive layer over the semiconductor substrate; forming an anti-reflective coating comprised of aluminum nitride directly on the conductive layer; depositing a resist over the anti-reflective coating; exposing selected portions of the resist to ultraviolet radiation having a wavelength of less than 300 nanometers; developing the resist to create a resist mask, the resist mask defining protected and unprotected regions of the anti-reflective coating and protected and unprotected regions of the conductive layer; and removing unprotected regions of the anti-reflective coating and unprotected regions of the conductive layer by etching.
Claim 2
Independent Claim
106 words
A method for making a semiconductor device, comprising the steps of: providing a semiconductor substrate; depositing a conductive layer over the semiconductor substrate; forming an anti-reflective coating comprised of aluminum nitride directly on the conductive layer; depositing a resist over the anti-reflective coating; exposing selected portions of the resist to ultraviolet radiation having a wavelength of less than 300 nanometers; developing the resist to create a resist mask, the resist mask defining protected and unprotected regions of the anti-reflective coating and protected and unprotected regions of the conductive layer; and removing unprotected regions of the anti-reflective coating and unprotected regions of the conductive layer by etching.
Claim 3
Dependent Claim
30 words
The method of claim 1 wherein the step of forming an anti-reflective coating comprises reactively sputter depositing the anti-reflective coating using an aluminum target in an environment comprised of nitrogen.
Claim 4
Dependent Claim
21 words
The method of claim 1 wherein the step of depositing a conductive layer comprises depositing a conductive layer comprised of aluminum.
Claim 5
Dependent Claim
21 words
The method of claim 1 wherein the step of depositing a conductive layer comprises depositing a conductive layer comprised of polysilicon.
Claim 6
Dependent Claim
27 words
The method of claim 1 wherein the step of depositing an anti-reflective coating comprises depositing an anti-reflective coating having a thickness of between 10 to 40 nanometers.
Claim 7
Dependent Claim
71 words
The method of claim 1 further comprising the steps of: removing the resist mask; depositing an interlayer dielectric over remaining portions of the anti-reflective coating and conductive layer; and etching an opening in the interlayer dielectric, wherein the opening overlies a portion of the anti-reflective coating, wherein etching is performed until exposing the portion of the anti-reflective coating, and wherein the portion of the anti-reflective coating serves as an etch stop.
Claim 8
Dependent Claim
90 words
The method of claim 6 wherein the step of depositing a conductive layer comprises depositing a conductive layer comprised of aluminum, wherein the step of depositing an anti-reflective coating comprises depositing an anti-reflective coating having a thickness of between 10 to 40 nanometers, and further comprising the steps of: depositing titanium on the portion of the anti-reflective coating exposed by the opening; and thermally reacting the titanium with the portion of the anti-reflective coating exposed by the opening to form a conductive intermetallic compound comprised of aluminum, nitrogen, and titanium.
Claim 9
Dependent Claim
36 words
The method of claim 1 further comprising the steps of: removing the resist mask; and removing remaining portions of the anti-reflective coating selective to remaining portions of the conductive layer using an etch employing phosphoric acid.
Claim 10
Dependent Claim
27 words
The method of claim 1 wherein the step of exposing comprises exposing selected portions of the resist to deep ultraviolet radiation having a wavelength of 248 nanometers.
Claim 11
Independent Claim
85 words
A method for making a semiconductor device, comprising the steps of: providing a semiconductor wafer having a reflective layer, wherein the reflective layer reflects ultraviolet radiation and is conductive; forming an anti-reflective layer directly on the reflective layer, wherein the anti-reflective layer comprises aluminum nitride; depositing resist over the anti-reflective layer; and exposing selected portions of the resist to ultraviolet radiation having a wavelength 300 nm, wherein the ultraviolet radiation is transmitted through the selected portions of the resist and absorbed by the anti-reflective layer.
Claim 12
Independent Claim
85 words
A method for making a semiconductor device, comprising the steps of: providing a semiconductor wafer having a reflective layer, wherein the reflective layer reflects ultraviolet radiation and is conductive; forming an anti-reflective layer directly on the reflective layer, wherein the anti-reflective layer comprises aluminum nitride; depositing resist over the anti-reflective layer; and exposing selected portions of the resist to ultraviolet radiation having a wavelength 300 nm, wherein the ultraviolet radiation is transmitted through the selected portions of the resist and absorbed by the anti-reflective layer.
Claim 13
Dependent Claim
27 words
The method of claim 10 wherein the step of exposing comprises exposing selected portions of the resist to deep ultraviolet radiation having a wavelength of 248 nanometers.
Claim 14
Dependent Claim
25 words
The method of claim 10 wherein the step of providing a semiconductor wafer comprises providing a semiconductor wafer having a reflective layer comprised of aluminum.
Claim 15
Dependent Claim
25 words
The method of claim 10 wherein the step of providing a semiconductor wafer comprises providing a semiconductor wafer having a reflective layer comprised of polysilicon.
Claim 16
Dependent Claim
25 words
The method of claim 10 wherein the step of forming an anti-reflective layer comprises sputter depositing using an aluminum target in an environment containing nitrogen.
Claim 17
Dependent Claim
92 words
The method of claim 10 further comprising steps of: developing the resist to create a resist mask; using the resist mask to etch unmasked portions of the anti-reflective layer and the reflective layer; removing the resist mask; depositing an oxide over remaining portions of the anti-reflective layer and conductive layer; and etching an opening in the oxide, wherein the opening overlies a portion of the anti-reflective layer, wherein etching is performed until exposing the portion of the anti-reflective layer, and wherein the portion of the anti-reflective layer serves as an etch stop.
Claim 18
Dependent Claim
60 words
The method of claim 10 further comprising the steps of: developing the resist to create a resist mask; using the resist mask to etch unmasked portions of the anti-reflective layer and the reflective layer; removing the resist mask; and removing remaining portions of the anti-reflective layer selective to remaining portions of the reflective layer using an etch employing phosphoric acid.
Claim 19
Dependent Claim
19 words
The method of claim 10 wherein the step of forming an anti-reflective layer comprises forming a doped anti-reflective layer.
References Cited (Backward Citations)
US3869322A
Cited
US4183040A
Cited
US4288256A
Cited
US4540914A
Cited
US4820611A
Cited
JPH01223750A
Cited
JPH01241125A
Cited
US5270263A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-06-11 | 1999-12-11 | 2000-06-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-06-11 | 2003-12-11 | 2004-06-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-06-11 | 2007-12-11 | 2008-06-11 | $7700.00 | Window Closed / Lapsed |