Patent US290929A successfully refreshed from Google Patents.
US5652084A
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Method for reduced pitch lithography
Assignee: DSS Technology Management Inc
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Filing: 1996-10-22
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Granted: 1997-07-29
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Expires: 2016-10-22
Abstract
Abstract A lithographic patterning process uses multiple exposures to provide for relatively reduced pitch for features of a single patterned layer. A first imaging layer is exposed to radiation in accordance with a first pattern and developed. The resulting patterned layer is stabilized. A second imaging layer is subsequently formed to surround the first patterned layer, exposed to radiation in accordance with a second pattern, and developed to form a second patterned layer. As the first patterned layer has been stabilized, the first patterned layer remains with the second patterned layer to produce a single patterned layer. For another embodiment, a single imaging layer is patterned by exposure to radiation in accordance with two separate patterns. An exposed portion of the imaging layer is suitably stabilized to withstand subsequent lithographic process steps.
Inventors
- 👤 James M. Cleeves
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 01:25
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/70; G03F7/70425; G03F7/70466; G03F7/0035; G03F7/20; G03F7/2022
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
130 words
A lithography method for semiconductor fabrication using a semiconductor wafer, comprising the steps of: (a) forming a first imaging layer over the semiconductor wafer; (b) patterning the first imaging layer in accordance with a first pattern to form a first patterned layer having a first feature; (c) stabilizing the first patterned layer; (d) forming a second imaging layer over the first pattern layer; and (e) patterning the second imaging layer in accordance with a second pattern to form a second patterned layer having a second feature distinct from the first feature, wherein the second patterned layer and the first patterned layer form a single patterned layer, and wherein the first and second features which are formed relatively closer to one another than is possible through a single exposure to radiation.
Claim 2
Dependent Claim
130 words
A lithography method for semiconductor fabrication using a semiconductor wafer, comprising the steps of: (a) forming a first imaging layer over the semiconductor wafer; (b) patterning the first imaging layer in accordance with a first pattern to form a first patterned layer having a first feature; (c) stabilizing the first patterned layer; (d) forming a second imaging layer over the first pattern layer; and (e) patterning the second imaging layer in accordance with a second pattern to form a second patterned layer having a second feature distinct from the first feature, wherein the second patterned layer and the first patterned layer form a single patterned layer, and wherein the first and second features which are formed relatively closer to one another than is possible through a single exposure to radiation.
Claim 3
Dependent Claim
14 words
The method of claim 1, wherein the first imaging layer includes a positive photoresist.
Claim 4
Dependent Claim
14 words
The method of claim 1, wherein the second imaging layer includes a positive photoresist.
Claim 5
Dependent Claim
44 words
The method of claim 1, wherein the patterning step (b) includes the steps of: (i) exposing a portion of the first imaging layer to radiation; and (ii) developing the first imaging layer such that the exposed portion dissolves to form the first patterned layer.
Claim 6
Dependent Claim
44 words
The method of claim 1, wherein the patterning step (e) includes the steps of: (i) exposing a portion of the second imaging layer to radiation; and (ii) developing the second imaging layer such that the exposed portion dissolves to form the second patterned layer.
Claim 7
Dependent Claim
27 words
The method of claim 1, wherein the patterning step (b) includes the step of exposing a portion of the first imaging layer to radiation through a mask.
Claim 8
Dependent Claim
27 words
The method of claim 1, wherein the patterning step (e) includes the step of exposing a portion of the second imaging layer to radiation through a mask.
Claim 9
Dependent Claim
24 words
The method of claim 1, wherein the stabilizing step (c) includes the step of using a PRIST technique to stabilize the first patterned layer.
Claim 10
Dependent Claim
24 words
The method of claim 1, wherein the stabilizing step (c) includes the step of using a silylation technique to stabilize the first patterned layer.
Claim 11
Dependent Claim
24 words
The method of claim 1, wherein the stabilizing step (c) includes: exposing the first patterned layer to radiation and heating the first patterned layer.
Claim 12
Dependent Claim
47 words
The method of claim 1, wherein the stabilizing step (c) includes exposing the first patterned layer to radiation having a wavelength in a range from approximately 200 nanometers to approximately 400 nanometers, and heating the first patterned layer at a temperature ramped to approximately 230 degrees Celsius.
Claim 13
Dependent Claim
15 words
The lithography method of claim 1, where the first and second features do not overlap.
Claim 14
Dependent Claim
127 words
A lithography method for semiconductor fabrication using a semiconductor wafer, comprising the steps of: (a) forming a first imaging layer over the semiconductor wafer; (b) patterning the first imaging layer in accordance with a first pattern to form a first patterned layer having a first disposable post; (c) stabilizing the first patterned layer; (d) forming a second imaging layer over the first patterned layer; and (e) patterning the second imaging layer in accordance with a second pattern to form a second patterned layer having a second disposable post, wherein the second patterned layer and the first patterned layer together form a single patterned layer, wherein the first and second disposable posts are formed relatively closer to one another than is possible through a single exposure to radiation.
Claim 15
Dependent Claim
127 words
A lithography method for semiconductor fabrication using a semiconductor wafer, comprising the steps of: (a) forming a first imaging layer over the semiconductor wafer; (b) patterning the first imaging layer in accordance with a first pattern to form a first patterned layer having a first disposable post; (c) stabilizing the first patterned layer; (d) forming a second imaging layer over the first patterned layer; and (e) patterning the second imaging layer in accordance with a second pattern to form a second patterned layer having a second disposable post, wherein the second patterned layer and the first patterned layer together form a single patterned layer, wherein the first and second disposable posts are formed relatively closer to one another than is possible through a single exposure to radiation.
Claim 16
Dependent Claim
15 words
The lithography method of claim 13, where the first and second features do not overlap.
Claim 17
Dependent Claim
119 words
A lithography method for semiconductor fabrication using a semiconductor wafer, comprising the steps of: (a) forming a first imaging layer over the semiconductor wafer; (b) patterning the first imaging layer in accordance with a first pattern to form a first patterned layer having a first feature; (c) stabilizing the first patterned layer; (d) forming a second imaging layer over the first patterned layer; and (e) patterning the second imaging layer in accordance with a second pattern to form a second patterned layer having a second feature, wherein the second patterned layer and the first patterned layer form a single patterned layer, the first and second features having a pitch which is not limited by a single exposure to radiation.
Claim 18
Dependent Claim
119 words
A lithography method for semiconductor fabrication using a semiconductor wafer, comprising the steps of: (a) forming a first imaging layer over the semiconductor wafer; (b) patterning the first imaging layer in accordance with a first pattern to form a first patterned layer having a first feature; (c) stabilizing the first patterned layer; (d) forming a second imaging layer over the first patterned layer; and (e) patterning the second imaging layer in accordance with a second pattern to form a second patterned layer having a second feature, wherein the second patterned layer and the first patterned layer form a single patterned layer, the first and second features having a pitch which is not limited by a single exposure to radiation.
Claim 19
Dependent Claim
15 words
The lithography method of claim 15, where the first and second features do not overlap.
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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) | 2000-07-28 | 2001-01-27 | 2001-07-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-07-28 | 2005-01-27 | 2005-07-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-07-28 | 2009-01-27 | 2009-07-29 | $7700.00 | Window Closed / Lapsed |