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US5249142A Expired / Lapsed US ⏱️ 0.0 years remaining

Indirect temperature-measurement of films formed on semiconductor wafers

Assignee: Tokyo Electron Ltd
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Filing: 1992-04-03
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Granted: 1993-09-28
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Expires: 2012-04-03
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Abstract

Abstract A method of measuring the temperature of a matter accurately, in non-contact fashion and without setting any emissivity comprising obtaining a spectral characteristics of absorbing electromagnetic waves inherent to a matter whose temperature is to be measured, obtaining those absorption peak wavelengths of the electromagnetic waves which correspond to two or more high points of electromagnetic wave absorption rate obtained from the spectral characteristics, measuring amounts of the electromagnetic waves, which have the absorption peak wavelengths, radiated from the temperature-measured matter, and calculating the temperature of the matter from blues of the radiant amounts of the electromagnetic waves thus measured.

Inventors

  • 👤 Eiichi Shirakawa
  • 👤 Masafumi Nomura
  • 👤 Kimiharu Matsumura

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-31 21:45
CPC Classifications
G; G01; G01J; G01J5/00; G01J5/60

Claims Analysis

Total Claims: 15
Claim 1
Independent Claim 263 words
A method of determining a temperature of a film formed on a semiconductor wafer mounted on a heating plate, said method comprising the steps of: filtering electromagnetic waves radiated from said film by means of a first filter substantially allowing only a first electromagnetic wave of said electromagnetic waves to pass through, said first electromagnetic wave having a specific wavelength selected to correspond to an electromagnetic wave absorption rate peak point appearing in first spectral characteristics of absorbing electromagnetic waves inherent to said film, and selected to be prevented from corresponding to an electromagnetic wave absorption rate peak point appearing in second spectral characteristics of absorbing electromagnetic waves inherent to said wafer, in order to decrease a background heat effect; filtering electromagnetic waves radiated from said film by means of a second filter substantially allowing only a second electromagnetic wave of said electromagnetic waves to pass through, said second electromagnetic wave having a specific wavelength selected to correspond to another electromagnetic wave absorption rate peak point appearing in said first spectral characteristics, and selected to be prevented from corresponding to an electromagnetic wave absorption rate peak point appearing in said second spectral characteristics, in order to decrease a background heat-effect; respectively detecting the first electromagnetic wave having passed through said first filter, and the second electromagnetic wave having passed through said second filter; respectively measuring the first radiant amount of the detected first electromagnetic wave, and the second radiant amount of the detected second electromagnetic wave; and calculating the temperature of said film from the values of said first and second radiant amounts.
Claim 2
Independent Claim 263 words
A method of determining a temperature of a film formed on a semiconductor wafer mounted on a heating plate, said method comprising the steps of: filtering electromagnetic waves radiated from said film by means of a first filter substantially allowing only a first electromagnetic wave of said electromagnetic waves to pass through, said first electromagnetic wave having a specific wavelength selected to correspond to an electromagnetic wave absorption rate peak point appearing in first spectral characteristics of absorbing electromagnetic waves inherent to said film, and selected to be prevented from corresponding to an electromagnetic wave absorption rate peak point appearing in second spectral characteristics of absorbing electromagnetic waves inherent to said wafer, in order to decrease a background heat effect; filtering electromagnetic waves radiated from said film by means of a second filter substantially allowing only a second electromagnetic wave of said electromagnetic waves to pass through, said second electromagnetic wave having a specific wavelength selected to correspond to another electromagnetic wave absorption rate peak point appearing in said first spectral characteristics, and selected to be prevented from corresponding to an electromagnetic wave absorption rate peak point appearing in said second spectral characteristics, in order to decrease a background heat-effect; respectively detecting the first electromagnetic wave having passed through said first filter, and the second electromagnetic wave having passed through said second filter; respectively measuring the first radiant amount of the detected first electromagnetic wave, and the second radiant amount of the detected second electromagnetic wave; and calculating the temperature of said film from the values of said first and second radiant amounts.
Claim 3
Dependent Claim 55 words
The method according to claim 1, wherein said method further comprises the steps of: producing first and second electrical signals representing said first and second radiant amounts respectively; inputting said first and second electrical signals into a computer so as to calculate the temperature of the object based on said first and second electrical signals.
Claim 4
Dependent Claim 24 words
The method according to claim 2, wherein Planck's law of radiation and the Newton-Raphson method are utilized in said step of calculating the temperature.
Claim 5
Dependent Claim 13 words
The method according to claim 2, wherein said electromagnetic waves are infrared rays.
Claim 6
Dependent Claim 37 words
The method according to claim 4, wherein said wafer is made of silicon, and said first and second electromagnetic waves are selected to be prevented from having a wavelength of about 9 μm or about 16 μm.
Claim 7
Dependent Claim 31 words
The method according to claim 5, wherein said film is a photoresist film, and said first and second electromagnetic waves have wavelengths of about 3 μm and about 7 μm, respectively.
Claim 8
Independent Claim 202 words
A method of determining a temperature of a film formed on a semiconductor wafer mounted on a heating plate, said method comprising the steps of: selecting first and second wavelengths corresponding to different electromagnetic wave absorption rate peak points which appear in the spectral characteristics of absorbing electromagnetic waves inherent to said film, said first and second wavelengths being selected to be prevented from corresponding to an electromagnetic wave absorption rate peak point appearing in spectral characteristics of absorbing electromagnetic waves inherent to said wafer; filtering electromagnetic waves radiated from said film by means of a first filter substantially allowing only a first electromagnetic wave having the first wavelength to pass through; filtering electromagnetic waves radiated from said film by means of a second filter substantially allowing only a second electromagnetic wave having the second wavelength to pass through; respectively detecting the first electromagnetic wave having passed through the first filter, and the second electromagnetic wave having passed through the second filter; respectively measuring the first radiant amount of the detected first electromagnetic wave and the second radiant amount of the detected second electromagnetic wave; and calculating the temperature of the film from the values of the first and second radiant amounts.
Claim 9
Independent Claim 202 words
A method of determining a temperature of a film formed on a semiconductor wafer mounted on a heating plate, said method comprising the steps of: selecting first and second wavelengths corresponding to different electromagnetic wave absorption rate peak points which appear in the spectral characteristics of absorbing electromagnetic waves inherent to said film, said first and second wavelengths being selected to be prevented from corresponding to an electromagnetic wave absorption rate peak point appearing in spectral characteristics of absorbing electromagnetic waves inherent to said wafer; filtering electromagnetic waves radiated from said film by means of a first filter substantially allowing only a first electromagnetic wave having the first wavelength to pass through; filtering electromagnetic waves radiated from said film by means of a second filter substantially allowing only a second electromagnetic wave having the second wavelength to pass through; respectively detecting the first electromagnetic wave having passed through the first filter, and the second electromagnetic wave having passed through the second filter; respectively measuring the first radiant amount of the detected first electromagnetic wave and the second radiant amount of the detected second electromagnetic wave; and calculating the temperature of the film from the values of the first and second radiant amounts.
Claim 10
Dependent Claim 33 words
The method according to claim 7, wherein said wafer is made of silicon, and said first and second wavelengths are selected to be prevented from being about 9 μm or about 16 μm.
Claim 11
Dependent Claim 28 words
The method according to claim 8, wherein said film is a photoresist film, and said first and second wavelengths are about 3 μm and about 7 μm, respectively.
Claim 12
Independent Claim 188 words
A method of determining a temperature of a film formed on a silicon wafer mounted on a heating plate, said method comprising the steps of: selecting first and second wavelengths corresponding to different electromagnetic wave absorption rate peak points which appear in spectral characteristics of absorbing electromagnetic waves inherent to said film, said first and second wavelengths being selected to be prevented from being about 9 μm or about 16 μm; filtering electromagnetic waves radiated from the film by means of a first filter substantially allowing only a first electromagnetic wave having the first wavelength to pass through; filtering electromagnetic waves radiated from the film by means of a second filter substantially allowing only a second electromagnetic wave having the second wavelength to pass through; respectively detecting the first electromagnetic wave having passed through the first filter, and the second electromagnetic wave having passed through the second filter; respectively measuring the first radiant amount of the detected first electromagnetic wave, and the second radiant amount of the detected second electromagnetic wave; and calculating the temperature of the film from the values of the first and second radiant amounts.
Claim 13
Independent Claim 188 words
A method of determining a temperature of a film formed on a silicon wafer mounted on a heating plate, said method comprising the steps of: selecting first and second wavelengths corresponding to different electromagnetic wave absorption rate peak points which appear in spectral characteristics of absorbing electromagnetic waves inherent to said film, said first and second wavelengths being selected to be prevented from being about 9 μm or about 16 μm; filtering electromagnetic waves radiated from the film by means of a first filter substantially allowing only a first electromagnetic wave having the first wavelength to pass through; filtering electromagnetic waves radiated from the film by means of a second filter substantially allowing only a second electromagnetic wave having the second wavelength to pass through; respectively detecting the first electromagnetic wave having passed through the first filter, and the second electromagnetic wave having passed through the second filter; respectively measuring the first radiant amount of the detected first electromagnetic wave, and the second radiant amount of the detected second electromagnetic wave; and calculating the temperature of the film from the values of the first and second radiant amounts.
Claim 14
Dependent Claim 23 words
The method according to claim 10, wherein said first and second wavelengths are selected within a range of from 2.5 to 20 μm.
Claim 15
Dependent Claim 28 words
The method according to claim 11, wherein said film is a photoresist film, and said first and second wavelengths are about 3 μm and about 7 [2m, respectively.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1996-09-27 1997-03-29 1997-09-28 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2000-09-27 2001-03-29 2001-09-28 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2004-09-27 2005-03-29 2005-09-28 $7700.00 Window Closed / Lapsed

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