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US6720114B1 Expired / Lapsed US ⏱️ 0.0 years remaining

Method of forming an alternating phase shift circuitry fabrication mask, method of forming a circuitry fabrication mask having a subtractive alternating phase shift region, and alternating phase shift mask

Assignee: Micron Technology Inc
•
Filing: 2000-08-21
•
Granted: 2004-04-13
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Expires: 2020-08-21
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Abstract

Abstract Disclosed are methods of forming alternating phase shift circuitry fabrication masks, methods of forming circuitry fabrication masks having a subtractive alternating phase shift region, and alternating phase shift masks. In one implementation, a method of forming an alternating phase shift circuitry fabrication mask incudes combining circuitry pattern data biasing and wet undercut etching of light transmissive substrate material adjacent phase shift regions of the mask in fabricating the mask. In one implementation, a method of forming an alternating phase shift circuitry fabrication mask includes combining circuitry pattern data biasing and wet undercut etching of light transmissive substrate material adjacent phase shift regions of the mask effective to achieve a first data biased pattern when using the mask to fabricate circuitry of a desired circuit pattern on another substrate. The first data biased pattern has at least some first resolution spacing falling between a discrete finite resolution spacing of which a writing tool used to fabricate the mask is capable of achieving.

Inventors

  • 👤 Amy A. Winder
  • 👤 Paul Chipman

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-08 10:01
CPC Classifications
G; G03; G03F; G03F1/00; G03F1/26; G03F1/30

Claims Analysis

Total Claims: 53
Claim 1
Independent Claim 74 words
A method of forming an alternating phase shift circuitry fabrication mask comprising combining both circuitry pattern data biasing of a masking layer in its formation and then wet undercut etching of light transmissive substrate material adjacent phase shift regions of the mask in fabricating the mask, the data biasing comprising forming at least some openings in the masking layer to be larger than features to be fabricated therewith on a substrate using the mask.
Claim 2
Independent Claim 74 words
A method of forming an alternating phase shift circuitry fabrication mask comprising combining both circuitry pattern data biasing of a masking layer in its formation and then wet undercut etching of light transmissive substrate material adjacent phase shift regions of the mask in fabricating the mask, the data biasing comprising forming at least some openings in the masking layer to be larger than features to be fabricated therewith on a substrate using the mask.
Claim 3
Independent Claim 71 words
A method of forming an alternating phase shift circuitry fabrication mask comprising combining both circuitry pattern data biasing of a masking layer in its formation and then wet undercut etching of light transmissive substrate material adjacent phase shift regions of the mask in fabricating the mask, the method being void of any undercut etching of the light transmissive substrate material beneath a masking layer adjacent non-phase shifted regions of the mask.
Claim 4
Independent Claim 71 words
A method of forming an alternating phase shift circuitry fabrication mask comprising combining both circuitry pattern data biasing of a masking layer in its formation and then wet undercut etching of light transmissive substrate material adjacent phase shift regions of the mask in fabricating the mask, the method being void of any undercut etching of the light transmissive substrate material beneath a masking layer adjacent non-phase shifted regions of the mask.
Claim 5
Dependent Claim 28 words
The method of claim 1 comprising dry etching the light transmissive substrate material to at least partially form the phase shift regions prior to the wet undercut etching.
Claim 6
Independent Claim 132 words
A method of forming an alternating phase shift circuitry fabrication mask comprising: providing a mask writing tool capable of producing at least first and second discrete finite resolution spacings but incapable of producing a discrete finite resolution spacing between the first and second resolution spacings; and using said writing tool and combining both circuitry pattern data biasing of a masking layer in its formation and then wet undercut etching of light transmissive substrate material adjacent phase shift regions of the mask effective to achieve a first data biased pattern when using the mask to fabricate circuitry of a desired circuit pattern on another substrate, the first data biased pattern having at least some resolution spacing falling within said first and second resolution spacings of which the writing tool is incapable of producing.
Claim 7
Independent Claim 132 words
A method of forming an alternating phase shift circuitry fabrication mask comprising: providing a mask writing tool capable of producing at least first and second discrete finite resolution spacings but incapable of producing a discrete finite resolution spacing between the first and second resolution spacings; and using said writing tool and combining both circuitry pattern data biasing of a masking layer in its formation and then wet undercut etching of light transmissive substrate material adjacent phase shift regions of the mask effective to achieve a first data biased pattern when using the mask to fabricate circuitry of a desired circuit pattern on another substrate, the first data biased pattern having at least some resolution spacing falling within said first and second resolution spacings of which the writing tool is incapable of producing.
Claim 8
Dependent Claim 24 words
The method of claim 4 being void of any undercut etching of the light transmissive substrate material adjacent non-phase shifted regions of the mask.
Claim 9
Dependent Claim 28 words
The method of claim 4 comprising dry etching the light transmissive substrate material to at least partially form the phase shift regions prior to the wet undercut etching.
Claim 10
Independent Claim 209 words
A method of forming a circuitry fabrication mask having a subtractive alternating phase shift region, comprising: providing a light shielding layer over a light transmissive substrate; determining a desired circuit pattern to be fabricated on another substrate using the mask, the desired circuit pattern comprising two adjacent features; forming first and second adjacent openings into the light shielding layer configured to form the respective two adjacent features, one of the first and second adjacent openings being data biased to be larger than the feature to be fabricated therewith on the another substrate; masking the other of the first and second adjacent openings while leaving the one of the first and second openings outwardly exposed; while the other opening is masked and the one of the first and second openings is outwardly exposed, dry etching the light transmissive substrate to at least partially form a phase shift region through the one opening as compared to the masked adjacent other opening; and while the other opening is masked and the one of the first and second openings is outwardly exposed, wet etching the light transmissive substrate relative to the light shielding layer through the one opening effective to undercut at least some of the light shielding layer proximate the one opening.
Claim 11
Independent Claim 209 words
A method of forming a circuitry fabrication mask having a subtractive alternating phase shift region, comprising: providing a light shielding layer over a light transmissive substrate; determining a desired circuit pattern to be fabricated on another substrate using the mask, the desired circuit pattern comprising two adjacent features; forming first and second adjacent openings into the light shielding layer configured to form the respective two adjacent features, one of the first and second adjacent openings being data biased to be larger than the feature to be fabricated therewith on the another substrate; masking the other of the first and second adjacent openings while leaving the one of the first and second openings outwardly exposed; while the other opening is masked and the one of the first and second openings is outwardly exposed, dry etching the light transmissive substrate to at least partially form a phase shift region through the one opening as compared to the masked adjacent other opening; and while the other opening is masked and the one of the first and second openings is outwardly exposed, wet etching the light transmissive substrate relative to the light shielding layer through the one opening effective to undercut at least some of the light shielding layer proximate the one opening.
Claim 12
Dependent Claim 35 words
The method of claim 7 wherein the other of the first and second adjacent openings is not data biased to be different in size than the feature to be fabricated therewith on the another substrate.
Claim 13
Dependent Claim 34 words
The method of claim 7 wherein the other of the first and second adjacent openings is data biased to be different in size than the feature to be fabricated therewith on the another substrate.
Claim 14
Dependent Claim 34 words
The method of claim 9 wherein the other of the first and second adjacent openings is data biased to be smaller in size than the feature to be fabricated therewith on the another substrate.
Claim 15
Dependent Claim 34 words
The method of claim 9 wherein the other of the first and second adjacent openings is data biased to be larger in size than the feature to be fabricated therewith on the another substrate.
Claim 16
Dependent Claim 12 words
The method of claim 7 wherein the light shielding layer comprises metal.
Claim 17
Dependent Claim 12 words
The method of claim 7 wherein the light transmissive substrate comprises quartz.
Claim 18
Dependent Claim 16 words
The method of claim 7 wherein the dry etching is conducted prior to the wet etching.
Claim 19
Dependent Claim 16 words
The method of claim 7 wherein the wet etching is conducted prior to the dry etching.
Claim 20
Dependent Claim 26 words
The method of claim 7 comprising unmasking the other opening intermediate the wet and dry etching and checking the phase intermediate the wet and dry etching.
Claim 21
Dependent Claim 31 words
The method of claim 7 wherein a masking material is utilized in the masking, the same masking material remaining on the substrate during both the dry etching and the wet etching.
Claim 22
Dependent Claim 16 words
The method of claim 7 wherein the wet etching substantially uniformly undercuts the light shielding layer.
Claim 23
Independent Claim 254 words
A method of forming a circuitry fabrication mask having a subtractive alternating phase shift region, comprising: providing a light shielding layer over a light transmissive substrate; determining a desired circuit pattern to be fabricated on another substrate using the mask; data biasing the circuit pattern to derive a data biased pattern having at least some first alternating features of the circuitry to have first mask openings which are larger than the respective features to be fabricated on the another substrate, and having at least some second alternating features of the circuitry to have second mask openings, the first mask openings alternating with the second mask openings; forming the data biased pattern into the light shielding layer including forming the alternating first mask openings and the alternating second mask openings into the light shielding layer; masking the second mask openings in the light shielding layer while leaving the first mask openings in the light shielding layer exposed; while the second mask openings are masked and the first mask openings in the light shielding layer are exposed, dry etching the light transmissive substrate to at least partially form alternating phase shift regions through the first openings as compared to the masked alternating second openings; and while the second mask openings are masked and the first mask openings in the light shielding layer are exposed, wet etching the light transmissive substrate relative to the light shielding layer through the first openings effective to undercut at least some of the light shielding layer proximate the first mask openings.
Claim 24
Independent Claim 254 words
A method of forming a circuitry fabrication mask having a subtractive alternating phase shift region, comprising: providing a light shielding layer over a light transmissive substrate; determining a desired circuit pattern to be fabricated on another substrate using the mask; data biasing the circuit pattern to derive a data biased pattern having at least some first alternating features of the circuitry to have first mask openings which are larger than the respective features to be fabricated on the another substrate, and having at least some second alternating features of the circuitry to have second mask openings, the first mask openings alternating with the second mask openings; forming the data biased pattern into the light shielding layer including forming the alternating first mask openings and the alternating second mask openings into the light shielding layer; masking the second mask openings in the light shielding layer while leaving the first mask openings in the light shielding layer exposed; while the second mask openings are masked and the first mask openings in the light shielding layer are exposed, dry etching the light transmissive substrate to at least partially form alternating phase shift regions through the first openings as compared to the masked alternating second openings; and while the second mask openings are masked and the first mask openings in the light shielding layer are exposed, wet etching the light transmissive substrate relative to the light shielding layer through the first openings effective to undercut at least some of the light shielding layer proximate the first mask openings.
Claim 25
Dependent Claim 31 words
The method of claim 19 wherein the second mask openings are not data biased to be different in size than the respective features to be fabricated therewith on the another substrate.
Claim 26
Dependent Claim 30 words
The method of claim 19 wherein the second mask openings are data biased to be different in size than the respective features to be fabricated therewith on the another substrate.
Claim 27
Dependent Claim 30 words
The method of claim 21 wherein the second mask openings are data biased to be smaller in size than the respective features to be fabricated therewith on the another substrate.
Claim 28
Dependent Claim 30 words
The method of claim 21 wherein the second mask openings are data biased to be larger in size than the respective features to be fabricated therewith on the another substrate.
Claim 29
Dependent Claim 16 words
The method of claim 19 wherein the dry etching is conducted prior to the wet etching.
Claim 30
Dependent Claim 16 words
The method of claim 19 wherein the wet etching is conducted prior to the dry etching.
Claim 31
Dependent Claim 31 words
The method of claim 19 wherein a masking material is utilized in the masking, the same masking material remaining on the substrate during both the dry etching and the wet etching.
Claim 32
Dependent Claim 27 words
The method of claim 19 comprising unmasking the second mask openings intermediate the wet and dry etching and checking the phase intermediate the wet and dry etching.
Claim 33
Independent Claim 347 words
A method of forming a circuitry fabrication mask having a subtractive alternating phase shift region, comprising: providing a light shielding layer over a light transmissive substrate; determining a desired circuit pattern to be fabricated on another substrate using the mask; providing a mask writing tool capable of producing at least first and second discrete finite resolution spacings but incapable of producing a discrete finite resolution spacing between the first and second resolution spacings; data biasing the circuit pattern to derive a first data biased pattern having at least some first resolution spacing between the first and second resolution spacings; deriving a second data biased pattern from the first data biased pattern to change the first resolution spacing to a second resolution spacing equaling one of the first and second discrete finite resolution spacings of which the writing tool is capable; forming the second biased pattern into the light shielding layer, the second data bias pattern having at least some first alternating features having first mask openings which are larger than the respective circuitry features to be fabricated on the another substrate, and having at least some second alternating features of the circuitry to have second mask openings, the first mask openings alternating with the second mask openings; masking the second mask openings in the light shielding layer while leaving the first mask openings in the light shielding layer exposed; while the second mask openings are masked and the first mask openings in the light shielding layer are exposed, dry etching the light transmissive substrate to at least partially form alternating phase shift regions through the first openings as compared to the masked alternating second openings; and while the second mask openings are masked and the first mask openings in the light shielding layer are exposed, wet etching the light transmissive substrate through the first openings effective to undercut at least some of the light shielding layer proximate the first mask openings to a degree effective to achieve the first data biased pattern when using the mask to fabricate circuitry of the desired circuit pattern on another substrate.
Claim 34
Independent Claim 347 words
A method of forming a circuitry fabrication mask having a subtractive alternating phase shift region, comprising: providing a light shielding layer over a light transmissive substrate; determining a desired circuit pattern to be fabricated on another substrate using the mask; providing a mask writing tool capable of producing at least first and second discrete finite resolution spacings but incapable of producing a discrete finite resolution spacing between the first and second resolution spacings; data biasing the circuit pattern to derive a first data biased pattern having at least some first resolution spacing between the first and second resolution spacings; deriving a second data biased pattern from the first data biased pattern to change the first resolution spacing to a second resolution spacing equaling one of the first and second discrete finite resolution spacings of which the writing tool is capable; forming the second biased pattern into the light shielding layer, the second data bias pattern having at least some first alternating features having first mask openings which are larger than the respective circuitry features to be fabricated on the another substrate, and having at least some second alternating features of the circuitry to have second mask openings, the first mask openings alternating with the second mask openings; masking the second mask openings in the light shielding layer while leaving the first mask openings in the light shielding layer exposed; while the second mask openings are masked and the first mask openings in the light shielding layer are exposed, dry etching the light transmissive substrate to at least partially form alternating phase shift regions through the first openings as compared to the masked alternating second openings; and while the second mask openings are masked and the first mask openings in the light shielding layer are exposed, wet etching the light transmissive substrate through the first openings effective to undercut at least some of the light shielding layer proximate the first mask openings to a degree effective to achieve the first data biased pattern when using the mask to fabricate circuitry of the desired circuit pattern on another substrate.
Claim 35
Dependent Claim 30 words
The method of claim 28 wherein the second mask openings are data biased to be smaller in size than the respective features to be fabricated therewith on the another substrate.
Claim 36
Dependent Claim 30 words
The method of claim 28 wherein the second mask openings are data biased to be larger in size than the respective features to be fabricated therewith on the another substrate.
Claim 37
Dependent Claim 16 words
The method of claim 28 wherein the dry etching is conducted prior to the wet etching.
Claim 38
Dependent Claim 16 words
The method of claim 28 wherein the wet etching is conducted prior to the dry etching.
Claim 39
Dependent Claim 191 words
An alternating phase shift mask comprising: a light transmissive substrate having an outer surface; a light shielding layer received over the light transmissive substrate outer surface, the light shielding layer comprising a circuitry pattern at least a portion of which has a first series of openings therethrough which alternate with a second series of openings therethrough, at least the first series of openings being data biased to be larger than respective circuitry features to be fabricated on another substrate using the mask, the first series of openings respectively comprising opposing sidewalls; subtractive phase shift opening regions in the light transmissive substrate aligned with the first series of openings, the phase shift opening regions respectively having opposing sidewalls which are below and laterally recessed outwardly of the respective sidewalls of the first series of openings in the light shielding layer in at least one cross section, the phase shift opening regions having respective bases; and the second series of openings defining therethrough a series of respective exposed second light transmissive substrate bases which are substantially coplanar with the light transmissive substrate outer surface upon which the light shielding layer is proximately received.
Claim 40
Dependent Claim 191 words
An alternating phase shift mask comprising: a light transmissive substrate having an outer surface; a light shielding layer received over the light transmissive substrate outer surface, the light shielding layer comprising a circuitry pattern at least a portion of which has a first series of openings therethrough which alternate with a second series of openings therethrough, at least the first series of openings being data biased to be larger than respective circuitry features to be fabricated on another substrate using the mask, the first series of openings respectively comprising opposing sidewalls; subtractive phase shift opening regions in the light transmissive substrate aligned with the first series of openings, the phase shift opening regions respectively having opposing sidewalls which are below and laterally recessed outwardly of the respective sidewalls of the first series of openings in the light shielding layer in at least one cross section, the phase shift opening regions having respective bases; and the second series of openings defining therethrough a series of respective exposed second light transmissive substrate bases which are substantially coplanar with the light transmissive substrate outer surface upon which the light shielding layer is proximately received.
Claim 41
Dependent Claim 37 words
The alternating phase shift mask of claim 33 wherein the second series of circuit openings are not data biased to be different in size than the respective circuitry features to be fabricated therewith on the another substrate.
Claim 42
Dependent Claim 36 words
The alternating phase shift mask of claim 33 wherein the second series of circuit openings are data biased to be different in size than the respective circuitry features to be fabricated therewith on the another substrate.
Claim 43
Dependent Claim 36 words
The alternating phase shift mask of claim 35 wherein the second series of circuit openings are data biased to be smaller in size than the respective circuitry features to be fabricated therewith on the another substrate.
Claim 44
Dependent Claim 36 words
The alternating phase shift mask of claim 35 wherein the second series of circuit openings are data biased to be larger in size than the respective circuitry features to be fabricated therewith on the another substrate.
Claim 45
Dependent Claim 15 words
The alternating phase shift mask of claim 35 wherein the light shielding layer comprises metal.
Claim 46
Dependent Claim 15 words
The alternating phase shift mask of claim 35 wherein the light transmissive substrate comprises quartz.
Claim 47
Dependent Claim 35 words
The method of claim 1 wherein the data biasing also comprises forming at least some openings in the masking layer to be smaller than features to be fabricated therewith on the substrate using the mask.
Claim 48
Dependent Claim 24 words
The method of claim 1 being void of any undercut etching of the light transmissive substrate material adjacent non-phase shifted regions of the mask.
Claim 49
Dependent Claim 28 words
The method of claim 2 comprising dry etching the light transmissive substrate material to at least partially form the phase shift regions prior to the wet undercut etching.
Claim 50
Independent Claim 77 words
A method of forming an alternating phase shift circuitry fabrication mask comprising combining both circuitry pattern data biasing of a masking layer in its formation and then wet undercut etching of light transmissive substrate material adjacent phase shift regions of the mask in fabricating the mask, the data biasing comprising forming at least some adjacent openings in the masking layer to be larger and smaller than features to be fabricated therewith on a substrate using the mask.
Claim 51
Independent Claim 77 words
A method of forming an alternating phase shift circuitry fabrication mask comprising combining both circuitry pattern data biasing of a masking layer in its formation and then wet undercut etching of light transmissive substrate material adjacent phase shift regions of the mask in fabricating the mask, the data biasing comprising forming at least some adjacent openings in the masking layer to be larger and smaller than features to be fabricated therewith on a substrate using the mask.
Claim 52
Dependent Claim 28 words
The method of claim 43 being void of any undercut etching of the light transmissive substrate material beneath the masking layer adjacent non-phase shifted regions of the mask.
Claim 53
Dependent Claim 28 words
The method of claim 43 comprising dry etching the light transmissive substrate material to at least partially form the phase shift regions prior to the wet undercut etching.

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