Patent US6749972B2 successfully refreshed from Google Patents.
US6749972B2
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US
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Optical proximity correction common process window maximization over varying feature pitch
Assignee: Taiwan Semiconductor Manufacturing Co TSMC Ltd
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Filing: 2002-01-15
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Granted: 2004-06-15
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Expires: 2022-01-15
Abstract
Abstract Maximizing a common process window for optical proximity correction (OPC)-modified features of a semiconductor design having varying pitch is disclosed. For each pitch within a semiconductor design, a bias needed at the pitch that maximizes a common process window for the number of pitches given a critical dimension (CD) specification for a semiconductor design of the photomask is determined. The original layout for the semiconductor design of the photomask is then modified by performing rule-based optical-proximity correction (OPC), including adding the bias determined at each pitch, to yield a modified layout for the semiconductor design of the photomask. The modified layout is further modified by performing model-based on the modified layout such that exposed semiconductor wafer CD's at each pitch are at least substantially equal to the CD specification for the pitch, to yield a final layout for the semiconductor design of the photomask.
Inventors
- 👤 Shinn-Sheng Yu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 06:04
CPC Classifications
G; G03; G03F; G03F1/00; G03F1/36; G03F7/00; G03F7/70; G03F7/70425; G03F7/70433; G03F7/70441
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
145 words
A method for producing a photomask for semiconductor photolithography processing comprising: for each pitch of a plurality of pitches within a semiconductor design, determining a bias needed at the pitch that maximizes a common process window for the plurality of pitches given a critical dimension (CD) specification for a semiconductor design of the photomask; modifying an original layout for the semiconductor design of the photomask by performing rule-based optical-proximity correction (OPC), including adding the bias determined at each pitch, to yield a modified layout for the semiconductor design of the photomask; and, further modifying the modified layout for the semiconductor design of the photomask by performing model-based OPC on the modified layout such that exposed semiconductor wafer CD's at each pitch are at least substantially equal to the CD specification for the pitch, to yield a final layout for the semiconductor design of the photomask.
Claim 2
Independent Claim
145 words
A method for producing a photomask for semiconductor photolithography processing comprising: for each pitch of a plurality of pitches within a semiconductor design, determining a bias needed at the pitch that maximizes a common process window for the plurality of pitches given a critical dimension (CD) specification for a semiconductor design of the photomask; modifying an original layout for the semiconductor design of the photomask by performing rule-based optical-proximity correction (OPC), including adding the bias determined at each pitch, to yield a modified layout for the semiconductor design of the photomask; and, further modifying the modified layout for the semiconductor design of the photomask by performing model-based OPC on the modified layout such that exposed semiconductor wafer CD's at each pitch are at least substantially equal to the CD specification for the pitch, to yield a final layout for the semiconductor design of the photomask.
Claim 3
Dependent Claim
18 words
The method of claim 1 , wherein determining the bias needed comprises determining the bias needed by simulation.
Claim 4
Dependent Claim
18 words
The method of claim 1 , wherein determining the bias needed comprises determining the bias needed by experiment.
Claim 5
Dependent Claim
34 words
The method of claim 1 , wherein modifying the original layout for the semiconductor design of the photomask by adding the bias determined at each pitch comprises retargeting the CD's of the original layout.
Claim 6
Dependent Claim
27 words
The method of claim 1 , wherein the common process window has a first axis measuring depth of focus (DOF) and a second axis measuring light-exposure dose.
Claim 7
Dependent Claim
20 words
The method of claim 5 , wherein the first axis is an x-axis and the second axis is a y-axis.
Claim 8
Dependent Claim
70 words
A photomask for semiconductor photolithography processing comprising: a semiconductor design having a critical dimension (CD) specification and having had applied thereto rule-based and model-based optical proximity correction (OPC), the rule-based OPC including application of biases determined at each of a plurality of pitches of the semiconductor design; a plurality of pitches within the semiconductor design; and, a maximized common process window for the plurality of pitches given the CD specification.
Claim 9
Dependent Claim
70 words
A photomask for semiconductor photolithography processing comprising: a semiconductor design having a critical dimension (CD) specification and having had applied thereto rule-based and model-based optical proximity correction (OPC), the rule-based OPC including application of biases determined at each of a plurality of pitches of the semiconductor design; a plurality of pitches within the semiconductor design; and, a maximized common process window for the plurality of pitches given the CD specification.
Claim 10
Dependent Claim
27 words
The photomask of claim 7 , wherein the common process window has a first axis measuring depth of focus (DOF) and a second axis measuring light-exposure dose.
Claim 11
Dependent Claim
20 words
The photomask of claim 8 , wherein the first axis is an x-axis and the second axis is a y-axis.
Claim 12
Dependent Claim
36 words
The photomask of claim 7 , wherein the maximized common process window is determined by determining a bias needed at each pitch that maximizes the common process window, and adding the bias determined at each pitch.
Claim 13
Dependent Claim
42 words
The photomask of claim 10 , wherein the maximized common process window is further determined by performing rule-based and model-based OPC such that exposed semiconductor wafer CD's at each pitch are at least substantially equal to the CD specification for the pitch.
Claim 14
Dependent Claim
24 words
The photomask of claim 10 , wherein determining the bias needed at each pitch comprises determining the bias needed at each pitch by simulation.
Claim 15
Dependent Claim
24 words
The photomask of claim 10 , wherein determining the bias needed at each pitch comprises determining the bias needed at each pitch by experiment.
Claim 16
Dependent Claim
166 words
A semiconductor device formed at least in part by a method comprising: positioning a photomask over a semiconductor wafer having a top layer of photoresist, the photomask having a maximized common process window for a plurality of pitches of a semiconductor design to which rule-based and model-based optical proximity correction (OPC) has been applied, given a critical dimension (CD) specification of the semiconductor design, the rule-based OPC including application of biases determined at each of a plurality of pitches of the semiconductor design; exposing the semiconductor wafer through the photomask positioned thereover, such that the top layer of photoresist includes exposed parts under clear parts of the photomask and unexposed parts under opaque parts of the photomask; developing the semiconductor wafer to remove the exposed parts of the top layer of photoresist; etching the semiconductor wafer where the wafer is revealed through the exposed parts of the top layer of photoresist that has been removed; and, removing the unexposed parts of the top layer of photoresist.
Claim 17
Dependent Claim
166 words
A semiconductor device formed at least in part by a method comprising: positioning a photomask over a semiconductor wafer having a top layer of photoresist, the photomask having a maximized common process window for a plurality of pitches of a semiconductor design to which rule-based and model-based optical proximity correction (OPC) has been applied, given a critical dimension (CD) specification of the semiconductor design, the rule-based OPC including application of biases determined at each of a plurality of pitches of the semiconductor design; exposing the semiconductor wafer through the photomask positioned thereover, such that the top layer of photoresist includes exposed parts under clear parts of the photomask and unexposed parts under opaque parts of the photomask; developing the semiconductor wafer to remove the exposed parts of the top layer of photoresist; etching the semiconductor wafer where the wafer is revealed through the exposed parts of the top layer of photoresist that has been removed; and, removing the unexposed parts of the top layer of photoresist.
Claim 18
Dependent Claim
28 words
The semiconductor device of claim 14 , wherein the common process window has a first axis measuring depth of focus (DOE) and a second axis measuring light-exposure dose.
Claim 19
Dependent Claim
21 words
The semiconductor device of claim 15 , wherein the first axis is an x-axis and the second axis is a y-axis.
Claim 20
Dependent Claim
37 words
The semiconductor device of claim 14 , wherein the maximized common process window is determined by determining a bias needed at each pitch that maximizes the common process window, and adding the bias determined at each pitch.
Claim 21
Dependent Claim
43 words
The semiconductor device of claim 17 , wherein the maximized common process window is further determined by performing rule-based and model-based OPC such that exposed semiconductor wafer CD's at each pitch are at least substantially equal to the CD specification for the pitch.
Claim 22
Dependent Claim
24 words
The semiconductor device of claim 17 , wherein determining the bias needed at each comprises determining the bias needed at each pitch by simulation.
Claim 23
Dependent Claim
24 words
The semiconductor device of claim 17 , wherein determining the bias needed at each comprises determining the bias needed at each pitch by experiment.
References Cited (Backward Citations)
US6544699B1
Cited
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 2007-06-15 | 2007-12-15 | 2008-06-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2011-06-15 | 2011-12-15 | 2012-06-15 | $3760.00 | Window Closed / Lapsed |
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