US5747388A
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Antireflection layer and process for lithographically structuring a layer
Assignee: Infineon Technologies AG
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Filing: 1995-03-20
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Granted: 1998-05-05
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Expires: 2015-03-20
Abstract
Abstract A thick layer formed of aSi or aSi/aSiN is used as an antireflection layer (3) in the lithographic structuring of layers (2) on a semiconductor substrate (1). A reflection suppression is based on absorption in the aSi layer and on interference in the aSiN layer. An optical decoupling of the background is achieved, with the result that the antireflection layer can be used universally.
Inventors
- 👤 Karl-Heinz Kusters
- 👤 Paul Kupper
- 👤 Gunther Czech
- 👤 Hellmut Joswig
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 20:32
CPC Classifications
H; H10; H10P; H10P76/00; G; G03; G03F; G03F7/00; G03F7/004; G03F7/09; G03F7/091; H10P76/20; H10P76/204; H10P76/2041; H10P76/2043; Y; Y10; Y10S; Y10S430/00; Y10S430/151; Y10S438/00; Y10S438/942; Y10S438/948; Y10S438/952
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
83 words
In a process for structuring a layer on a semiconductor substrate using a photoresist mask and an etching process, the improvement which comprises: applying an aSi/aSiN double layer as an antireflection layer before generating the photoresist mask; and adjusting a layer thickness d of the aSi layer to essentially satisfy a condition d≧-ln (I/I o )/α(λ), where α(λ) is an absorption coefficient of the aSi layer at an exposure wavelength λ and (1-I/I o ) is a given absorption in the antireflection layer.
Claim 2
Dependent Claim
83 words
In a process for structuring a layer on a semiconductor substrate using a photoresist mask and an etching process, the improvement which comprises: applying an aSi/aSiN double layer as an antireflection layer before generating the photoresist mask; and adjusting a layer thickness d of the aSi layer to essentially satisfy a condition d≧-ln (I/I o )/α(λ), where α(λ) is an absorption coefficient of the aSi layer at an exposure wavelength λ and (1-I/I o ) is a given absorption in the antireflection layer.
Claim 3
Dependent Claim
62 words
The process according to claim 1, which comprises: applying the antireflection layer to the layer to be structured; generating the photoresist mask by applying, exposing and developing a photoresist; removing the antireflection layer with an etching process at points being laid bare; removing the layer to be structured with an etching process at points being laid bare; and removing the photoresist mask.
Claim 4
Dependent Claim
37 words
The process according to claim 2, which comprises carrying out the step of removing the photoresist mask in an etching process, before the step of removing the layer to be structured at the points being laid bare.
Claim 5
Dependent Claim
29 words
The process according to claim 1, which comprises forming the antireflection layer by placing a 45-65 nm thick aSiN layer on top of a 70-100 nm thick aSi layer.
Claim 6
Dependent Claim
13 words
The process according to claim 2, which comprises subsequently removing the antireflection layer.
Claim 7
Dependent Claim
13 words
The process according to claim 2, which comprises subsequently oxidizing the antireflection layer.
Claim 8
Dependent Claim
17 words
The process according to claim 1, which comprises forming the layer to be structured as a multilayer.
Claim 9
Dependent Claim
65 words
The process according to claim 2, which comprises: forming the layer to be structured as a multilayer having an upper sublayer and a lower sublayer; and removing the layer to be structured at the points being laid bare by initially only removing the upper sublayer, and removing the lower sublayer in an etching process at its points being laid bare, following the last process step.
Claim 10
Dependent Claim
71 words
The process according to claim 2, which comprises: forming the layer to be structured as a multilayer having an upper sublayer and a lower sublayer; and removing the layer to be structured at the points being laid bare by initially only removing the upper sublayer, and removing the lower sublayer in an etching process at its points being laid bare, at the same time as the removal of the antireflection layer.
Claim 11
Dependent Claim
31 words
The process according to claim 8, which comprises initially removing the aSiN layer and then simultaneously removing the aSi layer and the lower sublayer, during the removal of the antireflection layer.
Claim 12
Dependent Claim
31 words
The process according to claim 9, which comprises initially removing the aSiN layer and then simultaneously removing the aSi layer and the lower sublayer, during the removal of the antireflection layer.
Claim 13
Dependent Claim
73 words
In a process for lithographic structuring of a layer or multilayer applied to a semiconductor substrate, the improvement which comprises: applying an aSi/aSiN double layer as an antireflection layer; and adjusting a layer thickness d of the aSi layer for essentially satisfying a condition d≧-ln (I/I o )/α(λ), where α(λ) is an absorption coefficient of the aSi layer at an exposure wavelength λ and (1-I/I0) is a given absorption in the antireflection layer.
Claim 14
Dependent Claim
73 words
In a process for lithographic structuring of a layer or multilayer applied to a semiconductor substrate, the improvement which comprises: applying an aSi/aSiN double layer as an antireflection layer; and adjusting a layer thickness d of the aSi layer for essentially satisfying a condition d≧-ln (I/I o )/α(λ), where α(λ) is an absorption coefficient of the aSi layer at an exposure wavelength λ and (1-I/I0) is a given absorption in the antireflection layer.
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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) | 2001-05-04 | 2001-11-03 | 2002-05-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-05-04 | 2005-11-03 | 2006-05-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-05-04 | 2009-11-03 | 2010-05-05 | $7700.00 | Window Closed / Lapsed |