US5795683A
Expired / Lapsed
US
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Method and a system for designing a photomask for use in manufacture of a semiconductor device
Assignee: Toshiba Corp
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Filing: 1996-03-27
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Granted: 1998-08-18
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Expires: 2016-03-27
Abstract
Abstract A method for designing a photomask, used in photolithography using partially coherent incident light, the photomask having a substrate on which a plurality of transparent regions and opaque regions are formed, the transparent regions including a phase shifter for providing the incident light transmitting through the transparent regions with a phase difference, the method comprising the steps of extracting combinations of patterns adjacent to each other within a distance of a threshold value S2 as adjacent pairs from patterns corresponding to the transparent regions, calculating difficulty of correction of the adjacent pairs, sorting the adjacent pairs in an descending order of the difficulty of correction, connecting the patterns in the adjacent pairs to one another, such that a pair of adjacent patterns are not connected to each other and loop cut is performed if a closed loop is formed by connecting the adjacent patterns, and a pair of adjacent patterns are logically connected if a closed loop is not formed by connecting the adjacent patterns, and determining phases of light transmitted through the patterns, so that a phase of one of a pair of patterns is opposite to that of the other, on the basis of an inversion relationship finally obtained by the connecting step.
Inventors
- 👤 Taiga Uno
- 👤 Kiyomi Koyama
- 👤 Kazuko Yamamoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 10:57
CPC Classifications
G; G03; G03F; G03F1/00; G03F1/26; G03F1/30
Claims Analysis
Total Claims: 39
Claim 1
Independent Claim
192 words
A method for designing a photomask, used in photolithography using partially coherent incident light, the photomask having a substrate on which a plurality of transparent regions and opaque regions are formed, at least one of the transparent regions including a phase shifter for providing the incident light transmitting through the transparent regions with a phase difference, the method comprising the steps of: executing a fetching process for fetching mask layout data representing a plurality of figures corresponding to the plurality of transparent regions; executing a first process for forming groups of figures adjacent to one another within a distance S1 from a plurality of figures corresponding to the plurality of transparent regions represented by the mask layout data, and determining phases of the figures in each of the groups such that paired figures adjacent to each other have opposite phases, thereby obtaining an improper group of paired figures adjacent to each other having the same phase; and executing a second process for determining phases of the figures, while an initial figure to initialize phases is successively changed in the improper group, thereby obtaining phase-improper portions and the result of the phase determination.
Claim 2
Independent Claim
192 words
A method for designing a photomask, used in photolithography using partially coherent incident light, the photomask having a substrate on which a plurality of transparent regions and opaque regions are formed, at least one of the transparent regions including a phase shifter for providing the incident light transmitting through the transparent regions with a phase difference, the method comprising the steps of: executing a fetching process for fetching mask layout data representing a plurality of figures corresponding to the plurality of transparent regions; executing a first process for forming groups of figures adjacent to one another within a distance S1 from a plurality of figures corresponding to the plurality of transparent regions represented by the mask layout data, and determining phases of the figures in each of the groups such that paired figures adjacent to each other have opposite phases, thereby obtaining an improper group of paired figures adjacent to each other having the same phase; and executing a second process for determining phases of the figures, while an initial figure to initialize phases is successively changed in the improper group, thereby obtaining phase-improper portions and the result of the phase determination.
Claim 3
Dependent Claim
71 words
The method for designing a photomask according to claim 1, further comprising a step of executing a process for sorting the results of the phase determination obtained in the second process in each of groups in an ascending order of the number of improper portions, and displaying an initial figure used to initialize phases, a result of the phase determination and the figures in the improper portion, in a sorted order.
Claim 4
Dependent Claim
83 words
The method for designing a photomask according to claim 1, further comprising a step of executing a process for sorting the result of the phase determination obtained in the second process in each of groups in an order of easiness of correction based on comparison and evaluation as to whether an improper portion is easy to correct, and displaying an initial figure used to initialize phases, a result of the phase determination and the figures in the improper portion, in a sorted order.
Claim 5
Dependent Claim
44 words
A semiconductor manufacturing system comprising: a layout data output unit for outputting photomask layout data; a designing unit for executing the method claimed in claim 1; and an exposure unit for executing an exposure process based on photomask data designed by the designing unit.
Claim 6
Independent Claim
194 words
A system for designing a photomask, used in photolithography using partially coherent incident light, the photomask having a substrate on which a plurality of transparent regions and opaque regions are formed, at least one of the transparent regions including a phase shifter for providing the incident light transmitting through the transparent regions with a phase difference, the system comprising: a fetching unit for fetching mask layout data representing a plurality of figures corresponding to the plurality of transparent regions; a first process unit for forming groups of figures adjacent to one another within a distance S1 from a plurality of figures corresponding to the plurality of transparent regions represented by the mask layout data fetched by the fetching unit, and determining phases of the figures in each of the groups such that paired figures adjacent to each other have opposite phases, thereby obtaining an improper group of paired figures adjacent to each other having the same phase; and a second process unit for determining phases of the figures, while an initial figure to initialize phases is successively changed in the improper group, and obtaining improper portions and the phase determination through determining the phases.
Claim 7
Independent Claim
194 words
A system for designing a photomask, used in photolithography using partially coherent incident light, the photomask having a substrate on which a plurality of transparent regions and opaque regions are formed, at least one of the transparent regions including a phase shifter for providing the incident light transmitting through the transparent regions with a phase difference, the system comprising: a fetching unit for fetching mask layout data representing a plurality of figures corresponding to the plurality of transparent regions; a first process unit for forming groups of figures adjacent to one another within a distance S1 from a plurality of figures corresponding to the plurality of transparent regions represented by the mask layout data fetched by the fetching unit, and determining phases of the figures in each of the groups such that paired figures adjacent to each other have opposite phases, thereby obtaining an improper group of paired figures adjacent to each other having the same phase; and a second process unit for determining phases of the figures, while an initial figure to initialize phases is successively changed in the improper group, and obtaining improper portions and the phase determination through determining the phases.
Claim 8
Independent Claim
200 words
A method for designing a photomask, used in photolithography using partially coherent incident light, the photomask having a substrate on which a plurality of transparent regions and opaque regions are formed, at least one of the transparent regions including a phase shifter for providing the incident light transmitting through the transparent regions with a phase difference, the method comprising the steps of: executing a fetching process for fetching mask layout data representing a plurality of figures corresponding to the plurality of transparent regions; executing a first process for forming groups of figures adjacent to one another within a distance S1 from a plurality of figures corresponding to the plurality of transparent regions represented by the mask layout data, and determining phases of the figures in each of the groups such that paired figures adjacent to each other have opposite phases, thereby obtaining an improper group of paired figures adjacent to each other having the same phase; and executing a third process for designating a plurality of initial figures to initialize phases in an improper portion group, determining phases of the designated figures, and obtaining an improper portion and the phase determination in each of combinations of the phase-determined initial figures.
Claim 9
Independent Claim
200 words
A method for designing a photomask, used in photolithography using partially coherent incident light, the photomask having a substrate on which a plurality of transparent regions and opaque regions are formed, at least one of the transparent regions including a phase shifter for providing the incident light transmitting through the transparent regions with a phase difference, the method comprising the steps of: executing a fetching process for fetching mask layout data representing a plurality of figures corresponding to the plurality of transparent regions; executing a first process for forming groups of figures adjacent to one another within a distance S1 from a plurality of figures corresponding to the plurality of transparent regions represented by the mask layout data, and determining phases of the figures in each of the groups such that paired figures adjacent to each other have opposite phases, thereby obtaining an improper group of paired figures adjacent to each other having the same phase; and executing a third process for designating a plurality of initial figures to initialize phases in an improper portion group, determining phases of the designated figures, and obtaining an improper portion and the phase determination in each of combinations of the phase-determined initial figures.
Claim 10
Dependent Claim
71 words
The method for designing a photomask according to claim 6, further comprising a step of executing a process for sorting the result of the phase determination obtained in the third process in each of groups in an ascending order of the number of improper portions, and displaying an initial figure used to initialize phases, a result of the phase determination and the figures in the improper portion, in a sorted order.
Claim 11
Dependent Claim
83 words
The method for designing a photomask according to claim 6, further comprising a step of executing a process for sorting the result of the phase determination obtained in the third process in each of groups in an order of easiness of correction based on comparison and evaluation as to whether an improper portion is easy to correct, and displaying an initial figure used to initialize phases, a result of the phase determination and the figures in the improper portion, in a sorted order.
Claim 12
Independent Claim
201 words
A system for designing a photomask, used in photolithography using partially coherent incident light, the photomask having a substrate on which a plurality of transparent regions and opaque regions are formed, at least one of the transparent regions including a phase shifter for providing the incident light transmitting through the transparent regions with a phase difference, the system comprising: a fetching unit for fetching mask layout data representing a plurality of figures corresponding to the plurality of transparent regions; a first process unit for forming groups of figures adjacent to one another within a distance S1 from a plurality of figures corresponding to the plurality of transparent regions represented by the mask layout data, determining phases of the figures in each of the groups such that paired figures adjacent to each other have opposite phases, and obtaining an improper group of paired figures adjacent to each other having the same phase; and a third process unit for designating a plurality of figures to initialize phases in an improper portion, determining phases of the designated figures, and obtaining the improper portions and the phase determination in each of combinations of the phase-determined figures of an improper portion group through determining the phases.
Claim 13
Independent Claim
201 words
A system for designing a photomask, used in photolithography using partially coherent incident light, the photomask having a substrate on which a plurality of transparent regions and opaque regions are formed, at least one of the transparent regions including a phase shifter for providing the incident light transmitting through the transparent regions with a phase difference, the system comprising: a fetching unit for fetching mask layout data representing a plurality of figures corresponding to the plurality of transparent regions; a first process unit for forming groups of figures adjacent to one another within a distance S1 from a plurality of figures corresponding to the plurality of transparent regions represented by the mask layout data, determining phases of the figures in each of the groups such that paired figures adjacent to each other have opposite phases, and obtaining an improper group of paired figures adjacent to each other having the same phase; and a third process unit for designating a plurality of figures to initialize phases in an improper portion, determining phases of the designated figures, and obtaining the improper portions and the phase determination in each of combinations of the phase-determined figures of an improper portion group through determining the phases.
Claim 14
Independent Claim
194 words
A method for designing a photomask, used in photolithography using partially coherent incident light, the photomask having a substrate on which a plurality of transparent regions and opaque regions are formed, at least one of the transparent regions including a phase shifter for providing the incident light transmitting through the transparent regions with a phase difference, the method comprising the steps of: extracting combinations of patterns adjacent to each other within a distance of a threshold value S2 as adjacent pairs from patterns corresponding to the transparent regions; aligning the extracted adjacent pairs under a predetermined condition; connecting the pair in the adjacent pairs, such that a pair of adjacent patterns are not connected to each other and loop cut is performed if a closed loop is formed by connecting the adjacent pair, and a pair of adjacent patterns are logically connected if a closed loop is not formed by connecting the adjacent patterns; and determining phases of light transmitted through the patterns, so that a phase of one of a pair of patterns is opposite to that of the other, on the basis of an inversion relationship finally obtained by the connecting step.
Claim 15
Independent Claim
194 words
A method for designing a photomask, used in photolithography using partially coherent incident light, the photomask having a substrate on which a plurality of transparent regions and opaque regions are formed, at least one of the transparent regions including a phase shifter for providing the incident light transmitting through the transparent regions with a phase difference, the method comprising the steps of: extracting combinations of patterns adjacent to each other within a distance of a threshold value S2 as adjacent pairs from patterns corresponding to the transparent regions; aligning the extracted adjacent pairs under a predetermined condition; connecting the pair in the adjacent pairs, such that a pair of adjacent patterns are not connected to each other and loop cut is performed if a closed loop is formed by connecting the adjacent pair, and a pair of adjacent patterns are logically connected if a closed loop is not formed by connecting the adjacent patterns; and determining phases of light transmitted through the patterns, so that a phase of one of a pair of patterns is opposite to that of the other, on the basis of an inversion relationship finally obtained by the connecting step.
Claim 16
Dependent Claim
50 words
The method for designing a photomask according to claim 10, wherein the aligning step is a step of calculating difficulty of correction of the adjacent pairs and sorting the adjacent pairs in a descending order of the difficulty of correction, and forming inversion relationship in order of the sorted pairs.
Claim 17
Dependent Claim
30 words
The method for designing a photomask according to claim 10, wherein the aligning step is a step of forming an inversion relationship in an order of the extracted adjacent pairs.
Claim 18
Dependent Claim
74 words
The method for designing a photomask according to claim 12, further comprising a step extracting pairs of patterns adjacent to each other within a distance S3, greater than a distance S2 which cannot be resolved when phases of an adjacent pair of patterns are the same, and forming inversion relationship in order as each other within the distance S2, and the distance S3 which is greater than the distance S2 in the extracted pairs.
Claim 19
Dependent Claim
33 words
The method for designing a photomask according to claim 13, wherein a value of S3 is determined to be a critical distance as to whether resolution is improved by providing the phase difference.
Claim 20
Dependent Claim
63 words
The method for designing a photomask according to claim 10, further comprising a step of storing data of a single or a plurality of adjacent pairs obtained by a NAND operation of an adjacent relationship and an inversion relationship, extracting an adjacent pair of the same phase from the stored data after determining phases, and indicating the extracted pairs as a phase-improper portion.
Claim 21
Dependent Claim
32 words
The method for designing a photomask according to claim 10, wherein the threshold value S2 is defined as a limit distance which can be resolved only by Levenson type phase shifting method.
Claim 22
Dependent Claim
45 words
The method for designing a photomask according to claim 10, further comprising a step of storing data of loop-cut adjacent pairs, extracting an adjacent pair of the same phase from the stored data after determining phases, and indicating the extracted pairs as a phase-improper portion.
Claim 23
Dependent Claim
88 words
The method for designing a photomask according to claim 10, further comprising a step of forming an adjacent relationship of pairs of patterns adjacent to each other within a distance S3, greater than a distance S2 which cannot be resolved when phases of an adjacent pair of patterns are the same, and sorting the adjacent pairs by designating a distance between patterns of S2 or smaller as a first key, and difficulty of correction as a second key, and forming inversion relationship in order of the sorted pairs.
Claim 24
Dependent Claim
33 words
The method for designing a photomask according to claim 18, wherein a value of S3 is determined to be a critical distance as to whether resolution is improved by providing the phase difference.
Claim 25
Independent Claim
148 words
A method for designing a photomask, used in photolithography using partially coherent incident light, the photomask having a substrate on which a plurality of transparent regions and opaque regions are formed, at least one of the transparent regions including a phase shifter for providing the incident light transmitting through the transparent regions with a phase difference, the method comprising the steps of: obtaining an adjacent relationship of patterns adjacent to each other within a distance of a threshold value S2 with respect to patterns corresponding to the transparent regions; extracting combinations of patterns adjacent to each other in every adjacent group which is connected in accordance with the adjacent relationship; and processing the steps of sorting the combinations in a descending order of difficulty of correction, forming an inversion relationship based on a result of sorting, and determining phases of the patterns in accordance with the inversion relationship.
Claim 26
Independent Claim
148 words
A method for designing a photomask, used in photolithography using partially coherent incident light, the photomask having a substrate on which a plurality of transparent regions and opaque regions are formed, at least one of the transparent regions including a phase shifter for providing the incident light transmitting through the transparent regions with a phase difference, the method comprising the steps of: obtaining an adjacent relationship of patterns adjacent to each other within a distance of a threshold value S2 with respect to patterns corresponding to the transparent regions; extracting combinations of patterns adjacent to each other in every adjacent group which is connected in accordance with the adjacent relationship; and processing the steps of sorting the combinations in a descending order of difficulty of correction, forming an inversion relationship based on a result of sorting, and determining phases of the patterns in accordance with the inversion relationship.
Claim 27
Dependent Claim
28 words
The method for designing a photomask according to claim 20, wherein the inversion relationship forming step is a step for forming an inversion relationship in a sorted order.
Claim 28
Dependent Claim
37 words
The method for designing a photomask according to claim 20, wherein the inversion relationship forming step is a step for forming an inversion relationship in an order of the extracted combinations of patterns in every adjacent group.
Claim 29
Dependent Claim
30 words
The method for designing a photomask according to claim 20, wherein the aligning step is a step of forming an inversion relationship in an order of the extracted adjacent pairs.
Claim 30
Dependent Claim
78 words
The method for designing a photomask according to claim 23, further comprising a step forming an adjacent relationship of pairs of patterns adjacent to each other within a distance S3, greater than a distance S2 which cannot be resolved when phases of an adjacent pair of patterns are the same, and forming inversion relationship in order as each other within the distance S2, and the distance S3 which is greater than the distance S2 in the extracted pairs.
Claim 31
Dependent Claim
63 words
The method for designing a photomask according to claim 20, further comprising a step of storing data of a single or a plurality of adjacent pairs obtained by a NAND operation of an adjacent relationship and an inversion relationship, extracting an adjacent pair of the same phase from the stored data after determining phases, and indicating the extracted pairs as a phase-improper portion.
Claim 32
Dependent Claim
32 words
The method for designing a photomask according to claim 20, wherein the threshold value S2 is defined as a limit distance which can be resolved only by Levenson type phase shifting method.
Claim 33
Dependent Claim
45 words
The method for designing a photomask according to claim 20, further comprising a step of storing data of loop-cut adjacent pairs, extracting an adjacent pair of the same phase from the stored data after determining phases, and indicating the extracted pairs as a phase-improper portion.
Claim 34
Dependent Claim
78 words
The method for designing a photomask according to claim 20, further comprising a step of forming an adjacent relationship of pairs of patterns adjacent to each other within a distance S3, greater than a distance S2 which cannot be resolved when phases of an adjacent pair of patterns are the same, and sorting the adjacent pairs by designating a distance between patterns of S2 or smaller as a first key, and difficulty of correction as a second key.
Claim 35
Dependent Claim
33 words
The method for designing a photomask according to claim 28, wherein a value of S3 is determined to be a critical distance as to whether resolution is improved by providing the phase difference.
Claim 36
Dependent Claim
38 words
The method for designing a photomask according to claim 28, further comprising a step of forming inversion relationship in the phase-improper group adjacent to each other, and determining phases of the patterns in accordance with the inversion relationships.
Claim 37
Independent Claim
132 words
A method for designing a photomask, used in photolithography using partially coherent incident light, the photomask having a substrate on which a plurality of transparent regions and opaque regions are formed, at least one of the transparent regions including a phase shifter for providing the incident light transmitting through the transparent regions with a phase difference, the method comprising the steps of: designating as S2 a distance which cannot be resolved when phases of an adjacent pair of patterns are the same, and as S3 a distance which is greater than the distance S2; first, determining phases of patterns adjacent to each other with the distance S2 or smaller; and thereafter, determining phases of patterns adjacent to each other with a distance greater than S2 and equal to or smaller than S3.
Claim 38
Independent Claim
132 words
A method for designing a photomask, used in photolithography using partially coherent incident light, the photomask having a substrate on which a plurality of transparent regions and opaque regions are formed, at least one of the transparent regions including a phase shifter for providing the incident light transmitting through the transparent regions with a phase difference, the method comprising the steps of: designating as S2 a distance which cannot be resolved when phases of an adjacent pair of patterns are the same, and as S3 a distance which is greater than the distance S2; first, determining phases of patterns adjacent to each other with the distance S2 or smaller; and thereafter, determining phases of patterns adjacent to each other with a distance greater than S2 and equal to or smaller than S3.
Claim 39
Dependent Claim
33 words
The method for designing a photomask according to claim 31, wherein a value of S3 is determined to be a critical distance as to whether resolution is improved by providing the phase difference.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-08-17 | 2002-02-16 | 2002-08-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-08-17 | 2006-02-16 | 2006-08-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-08-17 | 2010-02-16 | 2010-08-18 | $7700.00 | Window Closed / Lapsed |