US5780208A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and mask design to minimize reflective notching effects
Assignee: Philips Semiconductors Inc
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Filing: 1996-10-17
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Granted: 1998-07-14
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Expires: 2016-10-17
Abstract
Abstract A method is described for reducing light scatter in lithographically producing a resist feature wherein the dosage of light beyond the immediate periphery of the desired feature is subjected to a lower dosage of light than is required to properly define the edges of the resist feature. In addition, a mask is described which is partially opaque in those areas remote from the area delineating the desired feature.
Inventors
- 👤 David Ziger
- 👤 Pierre Leroux
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 17:44
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/20; G03F1/00; G03F1/50
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
91 words
A method of reducing light scatter while lithographically producing a resist feature on a microcircuit substrate having an uneven topography comprising: a) providing a resist layer on the substrate and topography; b) providing a source of radiation; c) blocking the transmission of said radiation to that portion of the resist layer defining the resist feature; d) directing said radiation to a narrow border area around said resist feature in sufficient dosage to define said resist feature; and e) directing an attenuated dosage of said radiation to areas outside said border area.
Claim 2
Independent Claim
91 words
A method of reducing light scatter while lithographically producing a resist feature on a microcircuit substrate having an uneven topography comprising: a) providing a resist layer on the substrate and topography; b) providing a source of radiation; c) blocking the transmission of said radiation to that portion of the resist layer defining the resist feature; d) directing said radiation to a narrow border area around said resist feature in sufficient dosage to define said resist feature; and e) directing an attenuated dosage of said radiation to areas outside said border area.
Claim 3
Dependent Claim
60 words
A method of reducing light scatter while lithographically producing a resist feature on a microcircuit substrate having an uneven topography as defined in claim 1 wherein the step of directing an attenuated dosage of said radiation to areas outside said border area comprises providing a dosage of approximately seventy five percent of the dosage directed to said narrow border area.
Claim 4
Dependent Claim
36 words
A method of reducing light scatter while lithographically producing a resist feature on a microcircuit substrate having an uneven topography as defined in claim 1 wherein said narrow border area is approximately 0.2 μm in width.
Claim 5
Dependent Claim
70 words
A method of reducing light scatter while lithographically producing a resist feature on a microcircuit substrate having an uneven topography as defined in claim 1 wherein the step of directing an attenuated dosage of said radiation to areas outside said border area comprises providing a mask between said source of radiation and said resist layer; said mask having partial opacity in areas corresponding to said areas outside said border area.
Claim 6
Dependent Claim
37 words
A method of reducing light scatter while lithographically producing a resist feature on a microcircuit substrate having an uneven topography as defined in claim 4 wherein the partial opacity of said mask is approximately twenty five percent.
Claim 7
Independent Claim
92 words
A method of reducing light scatter while lithographically producing a resist feature on a microcircuit substrate having an uneven topography comprising: a) providing a resist layer on the substrate and topography; b) providing a source of radiation; c) blocking the transmission of said radiation to a first portion of said resist layer; d) directing an attenuated dosage of said radiation to a second portion of said resist layer; and e) directing a full dosage of said radiation to a narrow border area between said first and second portions of said resist layer.
Claim 8
Independent Claim
92 words
A method of reducing light scatter while lithographically producing a resist feature on a microcircuit substrate having an uneven topography comprising: a) providing a resist layer on the substrate and topography; b) providing a source of radiation; c) blocking the transmission of said radiation to a first portion of said resist layer; d) directing an attenuated dosage of said radiation to a second portion of said resist layer; and e) directing a full dosage of said radiation to a narrow border area between said first and second portions of said resist 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) | 2001-07-13 | 2002-01-12 | 2002-07-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-07-13 | 2006-01-12 | 2006-07-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-07-13 | 2010-01-12 | 2010-07-14 | $7700.00 | Window Closed / Lapsed |