US5358806A
Expired / Lapsed
US
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Phase shift mask, method of correcting the same and apparatus for carrying out the method
Assignee: Hitachi Ltd
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Filing: 1992-03-19
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Granted: 1994-10-25
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Expires: 2012-03-19
Abstract
Abstract A defect of a phase shift mask, which has a phase shifter disposed on a transparent substrate, formed into a predetermined pattern and acting to shift a phase of exposure light transmitted therethrough and an etching stopper disposed between the phase shifter and the transparent substrate, which is resistant to an etching to which the phase shifter is subjected and transparent for exposure light is corrected by selectively etching a defective portion of the phase shifter, having a lacking type defect, with respect to the etching stopper layer along the whole thickness of the phase shifter and by perforating a portion of the etching stopper layer and the transparent substrate positioned under the etched defective portion by a depth which corresponds to a magnitude of an optical path of the phase shifter for the exposure light, the etching being a reactive etching which uses charged particle beam and a reactive gas and, the bottom surface of a portion etched being flattened by utilizing a fact that the phase shifter is selectively etched.
Inventors
- 👤 Satoshi Haraichi
- 👤 Fumikazu Itoh
- 👤 Akira Shimase
- 👤 Hiroshi Yamaguchi
- 👤 Junzou Azuma
- 👤 Yasuhiro Koizumi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 21:11
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/02; H01J37/22; H01J37/226; H01J37/228; G; G03; G03F; G03F1/00; G03F1/68; G03F1/72; G03F1/74; H01J37/30; H01J37/305; H01J37/3053; H01J37/3056; G03F1/26; H01J2237/00; H01J2237/248; H01J2237/2482; H01J2237/30; H01J2237/304; H01J2237/30466
Claims Analysis
Total Claims: 34
Claim 1
Independent Claim
114 words
A phase shift mask comprising: a transparent substrate; and a phase shifter disposed on said transparent substrate, said phase shifter being formed into a predetermined pattern and acting to shift a phase of exposure light transmitted therethrough by a predetermined magnitude; wherein an etching stopper layer which is resistant to an etching to which said phase shifter is subjected and transparent for the exposure light is disposed between said phase shifter and said transparent substrate; and wherein said etching stopper layer has a thickness corresponding to a negligible magnitude of an optical path for the exposure light as compared with the length of the optical path for the exposure light in said phase shifter.
Claim 2
Dependent Claim
114 words
A phase shift mask comprising: a transparent substrate; and a phase shifter disposed on said transparent substrate, said phase shifter being formed into a predetermined pattern and acting to shift a phase of exposure light transmitted therethrough by a predetermined magnitude; wherein an etching stopper layer which is resistant to an etching to which said phase shifter is subjected and transparent for the exposure light is disposed between said phase shifter and said transparent substrate; and wherein said etching stopper layer has a thickness corresponding to a negligible magnitude of an optical path for the exposure light as compared with the length of the optical path for the exposure light in said phase shifter.
Claim 3
Dependent Claim
17 words
A mask according to claim 1, wherein said etching stopper layer is made of a metal halide.
Claim 4
Dependent Claim
26 words
A mask according to claim 2, wherein said metal halide is a material selected from a group consisting essentially of MgF 2 and CeF 3 .
Claim 5
Dependent Claim
113 words
A phase shift mask comprising: a transparent substrate; and a phase shifter disposed on said transparent substrate, said phase shifter being formed into a predetermined pattern and acting to shift a phase of exposure light transmitted therethrough by a predetermined magnitude; wherein an etching stopper layer which is resistant to an etching to which said phase shifter is subjected and transparent for the exposure light is disposed between said phase shifter and said transparent substrate; and wherein said etching stopper layer has a thickness corresponding to a magnitude of an optical path for exposure light which is the same as that of the optical path for said exposure light in said phase shifter.
Claim 6
Dependent Claim
113 words
A phase shift mask comprising: a transparent substrate; and a phase shifter disposed on said transparent substrate, said phase shifter being formed into a predetermined pattern and acting to shift a phase of exposure light transmitted therethrough by a predetermined magnitude; wherein an etching stopper layer which is resistant to an etching to which said phase shifter is subjected and transparent for the exposure light is disposed between said phase shifter and said transparent substrate; and wherein said etching stopper layer has a thickness corresponding to a magnitude of an optical path for exposure light which is the same as that of the optical path for said exposure light in said phase shifter.
Claim 7
Dependent Claim
17 words
A mask according to claim 4, wherein said etching stopper layer is made of a metal halide.
Claim 8
Dependent Claim
26 words
A mask according to claim 5, wherein said metal halide is a material selected from a group consisting essentially of MgF 2 and CeF 3 .
Claim 9
Dependent Claim
181 words
A defect-corrected phase shift mask comprising: a transparent substrate; and a phase shifter disposed on said transparent substrate, said phase shifter being formed into a predetermined pattern and acting to shift a phase of exposure light transmitted therethrough by a predetermined magnitude; wherein an etching stopper layer which is resistant to etching to which said phase shifter is subjected and transparent for the exposure light is disposed between said phase shifter and said transparent substrate, said etching stopper layer having a thickness corresponding to a negligible magnitude of an optical path for the exposure light as compared with the magnitude of the optical path for the exposure light in said phase shifter; wherein said mask has a hole extending from an upper surface of said phase shifter into said substrate through said etching stopper layer, a depth of the hole corresponding to a magnitude of an optical path of the phase shifter for the exposure light; and wherein said etching stopper layer is made of a material selected from a group consisting essentially of a metal oxide and a metal halide.
Claim 10
Dependent Claim
181 words
A defect-corrected phase shift mask comprising: a transparent substrate; and a phase shifter disposed on said transparent substrate, said phase shifter being formed into a predetermined pattern and acting to shift a phase of exposure light transmitted therethrough by a predetermined magnitude; wherein an etching stopper layer which is resistant to etching to which said phase shifter is subjected and transparent for the exposure light is disposed between said phase shifter and said transparent substrate, said etching stopper layer having a thickness corresponding to a negligible magnitude of an optical path for the exposure light as compared with the magnitude of the optical path for the exposure light in said phase shifter; wherein said mask has a hole extending from an upper surface of said phase shifter into said substrate through said etching stopper layer, a depth of the hole corresponding to a magnitude of an optical path of the phase shifter for the exposure light; and wherein said etching stopper layer is made of a material selected from a group consisting essentially of a metal oxide and a metal halide.
Claim 11
Independent Claim
202 words
A method of correcting a defect of a phase shift mask, said phase shift mask having a phase shifter disposed on a transparent substrate and an etching stopper layer disposed between said phase shifter and said transparent substrate, said phase shifter being formed into a predetermined pattern and acting to shift a phase of exposure light transmitted therethrough, said etching stopper layer being resistant to an etching to which said phase shifter is subjected and transparent for the exposure light, said method comprising the steps of: etching a defective portion of said phase shifter having a lacking-type defect selectively with respect to said etching stopper layer along a whole thickness of said phase shifter; and perforating a portion of said etching stopper layer and said transparent substrate positioned under said etched defection portion by a depth which corresponds to a magnitude of an optical path of said phase shifter for exposure light; wherein said step of etching the defect of said phase shifter is a reactive etching which uses a charged particle beam and a reactive gas and, in said etching step, the bottom surface of a portion etched is flattened by utilizing a fact that said phase shifter is selectively etched.
Claim 12
Independent Claim
202 words
A method of correcting a defect of a phase shift mask, said phase shift mask having a phase shifter disposed on a transparent substrate and an etching stopper layer disposed between said phase shifter and said transparent substrate, said phase shifter being formed into a predetermined pattern and acting to shift a phase of exposure light transmitted therethrough, said etching stopper layer being resistant to an etching to which said phase shifter is subjected and transparent for the exposure light, said method comprising the steps of: etching a defective portion of said phase shifter having a lacking-type defect selectively with respect to said etching stopper layer along a whole thickness of said phase shifter; and perforating a portion of said etching stopper layer and said transparent substrate positioned under said etched defection portion by a depth which corresponds to a magnitude of an optical path of said phase shifter for exposure light; wherein said step of etching the defect of said phase shifter is a reactive etching which uses a charged particle beam and a reactive gas and, in said etching step, the bottom surface of a portion etched is flattened by utilizing a fact that said phase shifter is selectively etched.
Claim 13
Dependent Claim
78 words
A method of correcting a defect of a mask according to claim 8, wherein said step of perforating said etching stopper includes a step in which a charged particle beam and a reactive gas for selectively etching said etching stopper layer with respect to said transparent substrate are used to selectively and chemically reactively etch the portion of said etching stopper layer under the defective portion of said phase shifter along the whole thickness of the stopper layer.
Claim 14
Dependent Claim
37 words
A method of correcting a defect of a mask according to claim 8, wherein said etching stopper layer is made of a material selected from a group consisting essentially of a metal oxide and a metal halide.
Claim 15
Dependent Claim
37 words
A method of correcting a defect of a mask according to claim 8, wherein said etching stopping layer is made of a metal halide selected from a group consisting essentially of MgF 2 and CeF 3 .
Claim 16
Independent Claim
157 words
A method of correcting a defect of a phase shift mask, said phase shift mask having a phase shifter disposed on a transparent substrate and an etching stopper layer disposed between said phase shifter and said transparent substrate, said phase shifter being formed into a predetermined pattern and acting to shift a phase of exposure light transmitted therethrough, said etching stopper layer being resistant to an etching to which said phase shifter is subjected and transparent for the exposure light, said method comprising the step of: selectively etching a residual-type defective portion of said phase shifter, said residual-type defective portion being made of the material of said phase shifter and being deposited on said transparent substrate outside said predetermined pattern, said selective etching being chemically reactive etching which uses a charged particle beam and a reactive gas, a bottom surface of an etched portion being flattened by utilizing a fact that said phase shifter is selectively etched.
Claim 17
Independent Claim
157 words
A method of correcting a defect of a phase shift mask, said phase shift mask having a phase shifter disposed on a transparent substrate and an etching stopper layer disposed between said phase shifter and said transparent substrate, said phase shifter being formed into a predetermined pattern and acting to shift a phase of exposure light transmitted therethrough, said etching stopper layer being resistant to an etching to which said phase shifter is subjected and transparent for the exposure light, said method comprising the step of: selectively etching a residual-type defective portion of said phase shifter, said residual-type defective portion being made of the material of said phase shifter and being deposited on said transparent substrate outside said predetermined pattern, said selective etching being chemically reactive etching which uses a charged particle beam and a reactive gas, a bottom surface of an etched portion being flattened by utilizing a fact that said phase shifter is selectively etched.
Claim 18
Dependent Claim
37 words
A method of correcting a defect of a mask according to claim 12, wherein said etching stopper layer is made of a material selected from a group consisting essentially of a metal oxide and a metal halide.
Claim 19
Dependent Claim
37 words
A method of correcting a defect of a mask according to claim 12, wherein said etching stopper layer is made of a metal halide selected from a group consisting essentially of MgF 2 and CeF 3 .
Claim 20
Independent Claim
136 words
A method of correcting a defect of a phase shift mask, said phase shift mask having a phase shifter disposed on a transparent substrate and an etching stopper layer disposed between said phase shifter and said transparent substrate, said phase shifter being formed into a predetermined pattern and acting to shift a phase of exposure light transmitted therethrough, said etching stopper layer being resistant to an etching to which said phase shifter is subjected and transparent for the exposure light, said method comprising the steps of: selectively etching a defective portion of said phase shifter having a lacking-type defect with respect to said etching stopper layer along a whole thickness of said phase shifter; and selectively etching a portion of said etching stopper layer positioned under said etched defective portion with respect to said transparent substrate.
Claim 21
Independent Claim
136 words
A method of correcting a defect of a phase shift mask, said phase shift mask having a phase shifter disposed on a transparent substrate and an etching stopper layer disposed between said phase shifter and said transparent substrate, said phase shifter being formed into a predetermined pattern and acting to shift a phase of exposure light transmitted therethrough, said etching stopper layer being resistant to an etching to which said phase shifter is subjected and transparent for the exposure light, said method comprising the steps of: selectively etching a defective portion of said phase shifter having a lacking-type defect with respect to said etching stopper layer along a whole thickness of said phase shifter; and selectively etching a portion of said etching stopper layer positioned under said etched defective portion with respect to said transparent substrate.
Claim 22
Independent Claim
175 words
A method of machining, with a focused ion beam, a phase shift mask having a phase shifter disposed on a transparent substrate, formed into a predetermined pattern and acting to shift a phase of exposure light transmitted therethrough and an etching stopper layer disposed between said phase shifter and said transparent substrate, which is resistant to an etching to which said phase shifter is subjected and transparent for the exposure light, comprising steps of: in order to correct a lacking type defect of said phase shifter, making a laser beam incident upon a surface of said mask which is being subjected to perforating with a focused ion beam; obtaining an interfered light by allowing a light beam reflected, by said surface to be perforated, of said incident laser beam and a reference laser beam obtained by reflecting said incident laser beam at a reference surface which is different from said surface to be perforated to interfere with each other; and monitoring a depth of perforation by detecting a change in said interfered light during perforating.
Claim 23
Independent Claim
175 words
A method of machining, with a focused ion beam, a phase shift mask having a phase shifter disposed on a transparent substrate, formed into a predetermined pattern and acting to shift a phase of exposure light transmitted therethrough and an etching stopper layer disposed between said phase shifter and said transparent substrate, which is resistant to an etching to which said phase shifter is subjected and transparent for the exposure light, comprising steps of: in order to correct a lacking type defect of said phase shifter, making a laser beam incident upon a surface of said mask which is being subjected to perforating with a focused ion beam; obtaining an interfered light by allowing a light beam reflected, by said surface to be perforated, of said incident laser beam and a reference laser beam obtained by reflecting said incident laser beam at a reference surface which is different from said surface to be perforated to interfere with each other; and monitoring a depth of perforation by detecting a change in said interfered light during perforating.
Claim 24
Independent Claim
55 words
A method of correcting a phase shift mask having a transparent substrate and a phase shifter disposed on said transparent substrate and formed into a predetermined pattern, said phase shifter having a lacking-type defect, said method comprising the step of: raising the refraction index of a lower region of said phase mask under the defect.
Claim 25
Independent Claim
55 words
A method of correcting a phase shift mask having a transparent substrate and a phase shifter disposed on said transparent substrate and formed into a predetermined pattern, said phase shifter having a lacking-type defect, said method comprising the step of: raising the refraction index of a lower region of said phase mask under the defect.
Claim 26
Dependent Claim
32 words
A mask correcting method according to claim 17, wherein said refraction index raising step is performed by implanting ions into said lower region by applying an ion beam to said lower region.
Claim 27
Dependent Claim
36 words
A mask correcting method according to claim 17, wherein said refraction index raising step is performed by generating thermal strain in said lower region by applying a beam for providing thermal energy to said lower region.
Claim 28
Dependent Claim
32 words
A mask correcting method according to claim 17, wherein said lower region is a region of said phase shifter positioned in a bottom portion of the lacking-type defect of said phase shifter.
Claim 29
Dependent Claim
44 words
A mask correcting method according to claim 20, wherein the bottom portion of the lacking-type defect is etched until it is made substantially flat, and a portion of said phase shifter which forms said flattened bottom portion is subjected to said refraction index raising.
Claim 30
Dependent Claim
45 words
A mask correcting method according to claim 17, wherein a portion of said phase shifter positioned below the lacking-type defect is removed by etching, and a portion of said transparent substrate which is exposed due to said removal is subjected to said refraction index raising.
Claim 31
Dependent Claim
39 words
A mask correcting method according to claim 22, wherein said transparent substrate includes a transparent conductive layer, and said transparent conductive layer is subjected to said refraction index raising at said portion of said transparent substrate which is exposed.
Claim 32
Dependent Claim
59 words
A phase shift mask comprising: a transparent substrate; and a phase shifter disposed on said transparent substrate, said phase shifter being formed into a predetermined pattern and acting to shift a phase of exposure light transmitted therethrough; wherein one of said transparent substrate and said phase shifter partially includes a portion the refraction index of which has been changed.
Claim 33
Dependent Claim
59 words
A phase shift mask comprising: a transparent substrate; and a phase shifter disposed on said transparent substrate, said phase shifter being formed into a predetermined pattern and acting to shift a phase of exposure light transmitted therethrough; wherein one of said transparent substrate and said phase shifter partially includes a portion the refraction index of which has been changed.
Claim 34
Dependent Claim
15 words
A mask according to claim 24, wherein said transparent substrate includes a transparent conductive layer.
References Cited (Backward Citations)
US4367119A
Cited
US5045417A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-10-24 | 1998-04-25 | 1998-10-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-10-24 | 2002-04-25 | 2002-10-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-10-24 | 2006-04-25 | 2006-10-25 | $7700.00 | Window Closed / Lapsed |