US5322748A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photomask and a method of manufacturing thereof comprising trapezoidal shaped light blockers covered by a transparent layer
Assignee: Renesas Electronics Corp
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Filing: 1992-08-21
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Granted: 1994-06-21
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Expires: 2012-08-21
Abstract
Abstract A photomask includes a transparent substrate, a light shielding film formed on the substrate, and a transparent film formed on the light shielding film and the substrate. The light shielding film has a bottom in contact with the substrate, a side face at an acute angle to the bottom, and an upper face in parallel with the bottom and at an obtuse angle to the side face. According to the light shielding film having such a configuration, a phase shift portion of a predetermined width and thickness can be formed accurately in the periphery of the light shielding film. The inferior influence of reflecting light with respect to the pattern resolution can be reduced if films of low reflectance are provided in the upper and lower portions of the light shielding film to improve the pattern resolution. The method of manufacturing this photomask includes the steps of patterning the light shielding film having a trapezoid configuration in which the upper base is shorter than the lower base on a transparent substrate, and forming a transparent film at a temperature of not more than 250° C. on the substrate and the light shielding film. The thermal distortion in the light shielding film can be suppressed effectively by the formation of a transparent film.
Inventors
- 👤 Yaichiro Watakabe
- 👤 Shuichi Matsuda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 11:06
CPC Classifications
G; G03; G03F; G03F1/00; G03F1/26; G03F1/29
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
86 words
A photomask comprising: a transparent substrate having adjacent first and second regions, a light shielding film formed on said first region on said substrate for preventing light from passing therethrough, including a bottom in contact with said substrate, a side face at an acute angle to said bottom, and an upper face in parallel with said bottom and at an obtuse angle to said side face, and a transparent film formed on said substrate so as to cover said light shielding film and said second region.
Claim 2
Dependent Claim
86 words
A photomask comprising: a transparent substrate having adjacent first and second regions, a light shielding film formed on said first region on said substrate for preventing light from passing therethrough, including a bottom in contact with said substrate, a side face at an acute angle to said bottom, and an upper face in parallel with said bottom and at an obtuse angle to said side face, and a transparent film formed on said substrate so as to cover said light shielding film and said second region.
Claim 3
Dependent Claim
19 words
The photomask structure according to claim 1, wherein the angle between said bottom and said side face is 70°-85°.
Claim 4
Dependent Claim
18 words
The photomask structure according to claim 1, wherein said light shielding film comprises silicon having impurities introduced therein.
Claim 5
Dependent Claim
27 words
The photomask structure according to claim 1, wherein said light shielding film comprises silicon having metal introduced therein for reducing the transparency of the light shielding film.
Claim 6
Dependent Claim
17 words
The photomask structure according to claim 1, wherein said transparent film comprises a film formed by sputtering.
Claim 7
Dependent Claim
18 words
The photomask structure according to claim 1, wherein said transparent film comprises a film formed by vacuum evaporation.
Claim 8
Dependent Claim
21 words
The photomask structure according to claim 1, wherein said transparent film comprises a film formed using an ECR plasma CVD method.
Claim 9
Dependent Claim
46 words
A photomask comprising: a transparent substrate having adjacent first and second regions, at a main surface, a first film of low reflectance selectively formed at said first region on said substrate, and a second film and formed on said first film and having light shielding function.
Claim 10
Dependent Claim
46 words
A photomask comprising: a transparent substrate having adjacent first and second regions, at a main surface, a first film of low reflectance selectively formed at said first region on said substrate, and a second film and formed on said first film and having light shielding function.
Claim 11
Dependent Claim
20 words
The photomask structure according to claim 8, wherein a third film of low reflectance is formed on said second film.
Claim 12
Dependent Claim
48 words
The photomask structure according to claim 8, wherein said second film comprises a bottom in contact with said first film, a side face at an acute angle to said bottom, and an upper face at an obtuse angle to said side face and in parallel with said bottom.
Claim 13
Dependent Claim
60 words
The photomask structure according to claim 8, wherein said second film comprises a bottom in contact with said first film, a side face at an acute angle to said bottom, and an upper face at an obtuse angle to said side face and in parallel with said bottom, a transparent film is formed on said first film and said substrate.
Claim 14
Dependent Claim
40 words
The photomask structure according to claim 8, wherein the material of said second film comprises metal or silicide, and the material of said first film comprises an oxide film, a nitride film, or an oxynitride film of said second film.
Claim 15
Dependent Claim
60 words
The photomask structure according to claim 9, wherein said second film comprises a bottom in contact with said first film, a side face at an acute angle to said bottom, and an upper face at an obtuse angle to said side face and in parallel with said bottom, a transparent film is formed on said third film and said substrate.
Claim 16
Independent Claim
56 words
A method of manufacturing a photomask comprising the steps of: patterning a light shielding film in a trapezoid configuration in which the upper base is shorter than the lower base on a transparent substrate, and forming a transparent film at a temperature of not more than 250° C. on said substrate and said light shielding film.
Claim 17
Independent Claim
56 words
A method of manufacturing a photomask comprising the steps of: patterning a light shielding film in a trapezoid configuration in which the upper base is shorter than the lower base on a transparent substrate, and forming a transparent film at a temperature of not more than 250° C. on said substrate and said light shielding film.
Claim 18
Dependent Claim
20 words
The method of manufacturing a photomask according to claim 14, wherein said transparent film is formed by a sputtering method.
Claim 19
Dependent Claim
21 words
The method of manufacturing a photomask according to claim 14, wherein said transparent film is formed by a vacuum evaporation method.
Claim 20
Dependent Claim
22 words
The method of manufacturing a photomask according to claim 14, wherein said transparent film is formed by an ECR plasma CVD method.
Claim 21
Dependent Claim
56 words
The method of manufacturing a photomask according to claim 14, wherein said step of patterning said light shielding film comprises the steps of forming a resist of a trapezoid configuration having an upper base shorter than the lower base on said light shielding film, and patterning said light shielding film with said resist as a mask.
Claim 22
Dependent Claim
20 words
The method of manufacturing a photomask according to claim 14, wherein said light shielding film is patterned by taper etching.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1997-06-20 | 1997-12-20 | 1998-06-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-06-20 | 2001-12-20 | 2002-06-21 | $3760.00 | Window Closed / Lapsed |
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