Patent US4865952A successfully refreshed from Google Patents.
US4865952A
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Method of forming a T-shaped control electrode through an X-ray mask
Assignee: Mitsubishi Electric Corp
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Filing: 1987-09-21
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Granted: 1989-09-12
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Expires: 2007-09-21
Abstract
Abstract A positive resist film is formed on the major surface of a semiconductor substrate, to be irradiated with X-rays through an X-ray mask. The X-ray mask is formed by a joined member of an X-ray transmittable substrate and an X-ray absorber, and the X-ray absorber has an opening section of a T shape, in order to change the amount of transmission of the X-rays in desired positions. After the irradiation with the X-rays, the positive resist film is developed to obtain a resist film having an opening section of a desired T shape. A film for providing a control electrode is formed in the opening section of the resist film and the resist film is removed, thereby to form a T-shaped control electrode on the semiconductor substrate.
Inventors
- 👤 Nobuyuki Yoshioka
- 👤 Noriaki Ishio
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 19:01
CPC Classifications
G; G03; G03F; G03F1/00; G03F1/22; G03F7/00; G03F7/20; G03F7/2037; G03F7/2039; H; H10; H10D; H10D30/00; H10D30/01; H10D30/061; H10D30/0612; H10D30/0614; H10D64/00; H10D64/01; H10D64/012; H10D64/0124; H10D64/0125; Y; Y10; Y10S; Y10S430/00; Y10S430/167; Y10S430/168; Y10S438/00; Y10S438/942; Y10S438/948; Y10S438/949
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
176 words
A method of forming a T-shaped control electrode having a section of a T shape by utilizing an X-ray mask, said method comprising the steps of: preparing a semiconductor substrate having a major surface; forming a positive resist film on said major surface of said semiconductor substrate; irradiating said positive resist film with X-rays through said X-ray mask, thereby to form respectively a first irradiated region corresponding to the width of a first portion of said T shape and obtaining a first intensity of exposure thereat and a second irradiated region corresponding to the width of a second portion of said T shape and obtaining a second intensity of exposure thereat on said positive resist film through said irradiation; developing said positive resist film irradiated with said X-rays to remove portions of said first and second irradiated regions, thereby to obtain a resist film having a sectional configuration corresponding to said T-shape; forming a film for providing a control electrode on a portion of said resist film having said sectional configuration; and removing said resist film.
Claim 2
Independent Claim
176 words
A method of forming a T-shaped control electrode having a section of a T shape by utilizing an X-ray mask, said method comprising the steps of: preparing a semiconductor substrate having a major surface; forming a positive resist film on said major surface of said semiconductor substrate; irradiating said positive resist film with X-rays through said X-ray mask, thereby to form respectively a first irradiated region corresponding to the width of a first portion of said T shape and obtaining a first intensity of exposure thereat and a second irradiated region corresponding to the width of a second portion of said T shape and obtaining a second intensity of exposure thereat on said positive resist film through said irradiation; developing said positive resist film irradiated with said X-rays to remove portions of said first and second irradiated regions, thereby to obtain a resist film having a sectional configuration corresponding to said T-shape; forming a film for providing a control electrode on a portion of said resist film having said sectional configuration; and removing said resist film.
Claim 3
Dependent Claim
42 words
A method of forming a T-shaped control electrode in accordance with claim 1, wherein: a first depth of development of said positive resist film based on said first exposure is at least equal to a film thickness of said positive resist film.
Claim 4
Dependent Claim
42 words
A method of forming a T-shaped control electrode in accordance with claim 2, wherein: a second depth of development of said positive resist film based on said second exposure is at least smaller than said film thickness of said positive resist film.
Claim 5
Independent Claim
163 words
A method of forming a T-shaped control electrode having a section of a T shape by utilizing an X-ray mask, said method comprising: a step of preparing a semiconductor substrate having a major surface; a step of forming a positive resist film on said major surface of said semiconductor substrate; a step of irradiating said positive resist film with X-rays through said X-ray mask formed by a joined member of a substrate for transmitting X-rays and an absorber for absorbing X-rays, said absorber having an opening section being in contact with said substrate and corresponding to said T shape thereby to change the amount of transmission of X-rays in desired positions; a step of developing said positive resist film irradiated with said X-rays to obtain a resist film having a desired sectional configuration; a step of forming a film for providing a control electrode in a portion of said resist film having said sectional configuration; and a step of removing said resist film.
Claim 6
Independent Claim
163 words
A method of forming a T-shaped control electrode having a section of a T shape by utilizing an X-ray mask, said method comprising: a step of preparing a semiconductor substrate having a major surface; a step of forming a positive resist film on said major surface of said semiconductor substrate; a step of irradiating said positive resist film with X-rays through said X-ray mask formed by a joined member of a substrate for transmitting X-rays and an absorber for absorbing X-rays, said absorber having an opening section being in contact with said substrate and corresponding to said T shape thereby to change the amount of transmission of X-rays in desired positions; a step of developing said positive resist film irradiated with said X-rays to obtain a resist film having a desired sectional configuration; a step of forming a film for providing a control electrode in a portion of said resist film having said sectional configuration; and a step of removing said resist film.
Claim 7
Dependent Claim
20 words
A method of forming a T-shaped control electrode in accordance with claim 4, wherein: said substrate comprises silicon nitride (SiN).
Claim 8
Dependent Claim
36 words
A method of forming a T-shaped control electrode in accordance with claim 5 wherein: said absorber comprises a metal having a large x-ray absorption coefficient, selected from a group of metals including gold, tungsten and tantalum.
Claim 9
Dependent Claim
17 words
A method of forming a T-shaped control electrode with claim 4, wherein: said film comprises gold (Au).
Claim 10
Independent Claim
163 words
A method of forming a T-shaped control electrode having a section of a T shape by employing an X-ray mask, said method comprising: a step of preparing a semiconductor substrate having a major surface, a step of forming a positive resist film on said major surface of said semiconductor substrate; a step of irradiating said positive resist film with divergent X-rays through said X-ray mask located at a first distance from said semiconductor substrate; a step of irradiating said positive resist film with said X-rays through said X-ray mask located at a second distance, that is selected to be different from said first distance, from said semiconductor substrate; a step of developing said positive resist film irradiated with said X-rays to obtain a resist film having a desired sectional configuration responsive to exposure; a step of forming a film for providing a control electrode in a portion of said resist film having said sectional configuration; and a step of removing said resist film.
Claim 11
Independent Claim
163 words
A method of forming a T-shaped control electrode having a section of a T shape by employing an X-ray mask, said method comprising: a step of preparing a semiconductor substrate having a major surface, a step of forming a positive resist film on said major surface of said semiconductor substrate; a step of irradiating said positive resist film with divergent X-rays through said X-ray mask located at a first distance from said semiconductor substrate; a step of irradiating said positive resist film with said X-rays through said X-ray mask located at a second distance, that is selected to be different from said first distance, from said semiconductor substrate; a step of developing said positive resist film irradiated with said X-rays to obtain a resist film having a desired sectional configuration responsive to exposure; a step of forming a film for providing a control electrode in a portion of said resist film having said sectional configuration; and a step of removing said resist film.
Claim 12
Dependent Claim
23 words
A method of forming a T-shaped control electrode in accordance with claim 8, wherein: said first distance is larger than said second distance.
Claim 13
Dependent Claim
23 words
A method of forming a T-shaped control electrode in accordance with claim 8, wherein: said second distance is larger than said first distance.
Claim 14
Dependent Claim
19 words
A method of forming a T-shaped control electrode in accordance with claim 8, wherein: said X-rays are characteristic X-rays.
Claim 15
Dependent Claim
19 words
A method of forming a T-shaped control electrode in accordance with claim 8, wherein: said X-rays are soft X-rays.
References Cited (Backward Citations)
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