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Manufacture of semiconductor device using a-c anti-reflection coating

Assignee: Fujitsu Semiconductor Ltd
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Filing: 1995-03-15
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Granted: 1998-05-12
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Expires: 2015-03-15
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Abstract

Abstract A method of manufacturing a semiconductor device including the steps of: forming a transparent oxide film on a light reflecting surface; forming an anti-reflective a-c film on the surface of the transparent film; and coating a photoresist film on the surface of the anti-reflective film and patterning the photoresist film, wherein the thicknesses of the anti-reflective film and the transparent film are selected so as to set a standing wave intensity I sw =Iδ/I ave to 0.2 or smaller, where I ave is an average value of light intensity in the photoresist film, and Iδ is an amplitude of a light intensity change. A fine pattern can be formed on a highly reflective substrate with a small size variation and at a high precision.

Inventors

  • 👤 Eiichi Kawamura
  • 👤 Teruyoshi Yao
  • 👤 Nobuhisa Naori
  • 👤 Koichi Hashimoto
  • 👤 Masaharu Kobayashi
  • 👤 Tadasi Oshima

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-30 10:40
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/004; G03F7/09; G03F7/091

Claims Analysis

Total Claims: 7
Claim 1
Independent Claim 183 words
A method of manufacturing a semiconductor device, said method comprising the steps of: forming a transparent film on a light reflecting surface, said transparent film having an absolute value 0.2 or smaller of an imaginary part of a complex refractive index; forming an anti-reflective film on a surface of said transparent film, said anti-reflective film having an absolute value 0.3 or larger of an imaginary part of a complex refractive index; and coating a photoresist film on a surface of said anti-reflective film and patterning said photoresist film by applying incident light to an area of said photoresist film, wherein thicknesses of said anti-reflective film and said transparent film are so selected as to provide a standing wave generated by a superposition of the incident light and reflected light reflected from said anti-reflective film, said transparent film, and said light reflecting surface, wherein an intensity of the standing wave I sw =Iδ/I ave to 0.2 or smaller, where I ave is an average value of light intensity in said photoresist film, and wherein Iδ is an amplitude of a change in light intensity.
Claim 2
Independent Claim 183 words
A method of manufacturing a semiconductor device, said method comprising the steps of: forming a transparent film on a light reflecting surface, said transparent film having an absolute value 0.2 or smaller of an imaginary part of a complex refractive index; forming an anti-reflective film on a surface of said transparent film, said anti-reflective film having an absolute value 0.3 or larger of an imaginary part of a complex refractive index; and coating a photoresist film on a surface of said anti-reflective film and patterning said photoresist film by applying incident light to an area of said photoresist film, wherein thicknesses of said anti-reflective film and said transparent film are so selected as to provide a standing wave generated by a superposition of the incident light and reflected light reflected from said anti-reflective film, said transparent film, and said light reflecting surface, wherein an intensity of the standing wave I sw =Iδ/I ave to 0.2 or smaller, where I ave is an average value of light intensity in said photoresist film, and wherein Iδ is an amplitude of a change in light intensity.
Claim 3
Dependent Claim 33 words
A method according to claim 1, wherein the thickness of said anti-reflective film is selected to have a value within ±20% of a film thickness which provides a minimum standing wave intensity Isw.
Claim 4
Dependent Claim 35 words
A method according to claim 1, wherein the thickness of said transparent film is selected to have a value within ±20% of a film thickness which provides a minimum standing wave intensity I sw .
Claim 5
Dependent Claim 70 words
A method according to claim 1, wherein the incident light incident to said photoresist film is an i-line having a wavelength of about 365 nm, wherein said anti-reflective film is formed as an amorphous carbon film having a thickness of 21 to 47 nm, said transparent film is an SiO 2 film having a thickness of 25 to 55 nm, and wherein the light reflecting surface is a WSi surface.
Claim 6
Dependent Claim 74 words
A method according to claim 1, wherein the incident light incident to said photoresist film has a wavelength of 228 to 268 nm, said anti-reflective film is formed as an amorphous carbon film having a thickness of 20 to 50 nm, said transparent film is formed as an SiO 2 film having a thickness of 5 to 30 nm or 70 to 110 nm, and wherein the light reflecting surface is a WSi surface.
Claim 7
Dependent Claim 50 words
A method according to claim 1, wherein said anti-reflective film is formed as one of an amorphous carbon film and a hydrocarbon compound film containing carbon and hydrogen, and said transparent film is formed as one of a silicon oxide film, a silicon nitride film, and an inorganic glass film.

References Cited (Backward Citations)

JPS60235426A Cited
DE4138999A1 Cited
US5437961A Cited
US5472829A Cited
JPH06342744A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2001-05-11 2001-11-10 2002-05-12 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2005-05-11 2005-11-10 2006-05-12 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2009-05-11 2009-11-10 2010-05-12 $7700.00 Window Closed / Lapsed

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