Patent US5601366A successfully refreshed from Google Patents.
US5601366A
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Method for temperature measurement in rapid thermal process systems
Assignee: Texas Instruments Inc
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Filing: 1994-10-25
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Granted: 1997-02-11
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Expires: 2014-10-25
Abstract
Abstract A method for obtaining real-time emissivity and temperature values of a semiconductor wafer in a processing system having at least one lamp (preferably a plurality of lamps arranged in a plurality of zones so as to provide multizone temperature and emissivity values for the semiconductor wafer) arranged in at least one zone, the method using a reference wafer having a known reflectivity and the method comprising the steps of: measuring pyrometry signals for the reference wafer (step 202) and generating calibration curves from the measurements; measuring pyrometry signals for the semiconductor wafer; and obtaining the temperature and emissivity values (step 222) from the calibration curves and the measured pyrometry signals (step 220) for the semiconductor wafer.
Inventors
- 👤 Ajit P. Paranjpe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 02:56
CPC Classifications
G; G01; G01J; G01J5/00; G01J5/0003
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
110 words
A method for real-time obtaining emissivity and temperature values of a semiconductor wafer in a processing system having at least one lamp arranged in at least one zone, said method using a reference wafer having a known reflectivity and said method comprising the steps of: measuring pyrometry signals for said reference wafer and generating calibration curves from said measurements; measuring pyrometry signals for said semiconductor wafer by time modulating said lamps so as to obtain a time-averaged component of said pyrometry signals and an amplitude-modulated component of said pyrometry signals; and obtaining said temperature and emissivity values from said calibration curves and said measured pyrometry signals for said semiconductor wafer.
Claim 2
Independent Claim
110 words
A method for real-time obtaining emissivity and temperature values of a semiconductor wafer in a processing system having at least one lamp arranged in at least one zone, said method using a reference wafer having a known reflectivity and said method comprising the steps of: measuring pyrometry signals for said reference wafer and generating calibration curves from said measurements; measuring pyrometry signals for said semiconductor wafer by time modulating said lamps so as to obtain a time-averaged component of said pyrometry signals and an amplitude-modulated component of said pyrometry signals; and obtaining said temperature and emissivity values from said calibration curves and said measured pyrometry signals for said semiconductor wafer.
Claim 3
Dependent Claim
35 words
The method of claim 1 wherein said at least one lamp is a plurality of lamps arranged in a plurality of zones so as to provide multizone temperature and emissivity values for said semiconductor wafer.
Claim 4
Dependent Claim
82 words
The method of claim 1 wherein said calibration curves are obtained according to the equation: ##EQU16## wherein: S c ,j is the measured pyrometry signal for said semiconductor wafer; and r c is the known reflectivity of the reference wafer; C 1 is a calibration constant; and f j (P j ) is lamp intensity and chamber radiation reflected from the semiconductor wafer within a wavelength interval of the pyrometer for lamp zone J at a give lamp power, P j .
Claim 5
Dependent Claim
63 words
The method of claim 1 wherein said amplitude-modulated component of said pyrometry signals can be determined by: ##EQU17## wherein: ∂S 100 ,j /∂P j is the slope of the calibration curve for S 100 ,j as a function of lamp power, P j ; P ac ,j is the amplitude-modulated component of lamp power; and r is the reflectance of the semiconductor wafer.
Claim 6
Dependent Claim
73 words
The method of claim 1 wherein said temperature can be obtained from the functional dependence of the Plank function, h(T), on temperature and utilizing this in: ##EQU18## wherein: S dc is the time-averaged value of the pyrometry signal; S 100 ,j (P dc ,j) represents individual points on the pyrometry calibration curve for a highly reflective wafer as a function of lamp power; and ε is the spectral emissivity of the semiconductor wafer.
Claim 7
Dependent Claim
64 words
The method of claim 1 wherein said emissivity is obtained from: ##EQU19## wherein: ε is the emissivity; r is the reflectance of the semiconductor wafer; S ac is the amplitude-modulated component of the pyrometry signal; P ac ,j is the amplitude-modulated component of the j th lamp power; and γ j is slope of the pyrometry calibration curve as a function of lamp power.
Claim 8
Dependent Claim
124 words
The method of claim 1 wherein said time-averaged component of said pyrometry signals can be obtained by: ##EQU20## wherein: C 1 is a calibration constant; P dc ,j is the time averaged (DC) power of lamp zone j; S max and S min are maximum and minimum values of said pyrometer signals; ε is the spectral emissivity of the wafer; g(T) the Planck function for the radiation intensity emitted by the wafer within the wavelength interval of the pyrometer; r is the reflectance of the semiconductor wafer; and f j (P dc ,j) is lamp intensity and chamber radiation reflected from the wafer within the wavelength interval of the pyrometer for lamp zone j at a given averaged lamp zone power (P dc ,j).
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-02-11 | 2000-08-12 | 2001-02-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-02-11 | 2004-08-12 | 2005-02-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-02-11 | 2008-08-12 | 2009-02-11 | $7700.00 | Window Closed / Lapsed |