US5213985A
Expired / Lapsed
US
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Temperature measurement in a processing chamber using in-situ monitoring of photoluminescence
Assignee: STANFORD UNIVERSITY OTL LLC
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Filing: 1991-05-22
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Granted: 1993-05-25
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Expires: 2011-05-22
Abstract
Abstract A relatively simple optical monitoring technique is utilized to measure temperature within a processing chamber. A III-V direct-bandgap semiconductor is optically excited to emit photoluminescence (PL). Spectral resolution of the emitted PL provides a direct measure of the bandgap of the semiconductor. In turn, the temperature of the semiconductor is derived from the bandgap measurement.
Inventors
- 👤 Claude J. Sandroff
- 👤 Francoise S. Sandroff
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 01:25
CPC Classifications
C; C30; C30B; C30B25/00; C30B25/02; B; B24; B24B; B24B37/00; B24B37/005; B24B37/013; G; G01; G01K; G01K11/00; G01K11/20; H; H10; H10P; H10P74/00; H10P74/23; H10P74/238; H10P74/20; H10P74/203
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
108 words
A method of measuring a parameter during fabrication of a microminiature device in an epitaxial growth gas phase or vacuum environment in a processing chamber, said method comprising the steps of positioning in said chamber in the direct vicinity of a device being fabricated therein a parameter monitoring element that comprises a III-V direct bandgap semiconductor, optically exciting said element to emit photoluminescence during fabrication of said device, and spectrally resolving the intensity of the photoluminescence emitted by said element to provide a measure of the bandgap energy of said element and thereby also of the parameter of the device fabrication processing being carried out in said chamber.
Claim 2
Independent Claim
108 words
A method of measuring a parameter during fabrication of a microminiature device in an epitaxial growth gas phase or vacuum environment in a processing chamber, said method comprising the steps of positioning in said chamber in the direct vicinity of a device being fabricated therein a parameter monitoring element that comprises a III-V direct bandgap semiconductor, optically exciting said element to emit photoluminescence during fabrication of said device, and spectrally resolving the intensity of the photoluminescence emitted by said element to provide a measure of the bandgap energy of said element and thereby also of the parameter of the device fabrication processing being carried out in said chamber.
Claim 3
Dependent Claim
18 words
A method as in claim 1 wherein optical excitation of said element is carried out by a laser.
Claim 4
Dependent Claim
44 words
A method as in claim 2 wherein spectral resolution is carried out by a monochromator and an intensity detector, said monochromator being positioned in the path of photoluminescence emitted by said element and said detector being positioned to receive the output of said monochromator.
Claim 5
Dependent Claim
26 words
A method as in claim 3 wherein the parameter being measured in said chamber in the direct vicinity of the device being fabricated therein is temperature.
Claim 6
Dependent Claim
45 words
A method as in claim 4 wherein a chopper is interposed in the path of optical excitation between said laser and said monitoring element, and lock-in circuitry operating in synchronism with said chopper is coupled to said detector for controlling the operation of said detector.
Claim 7
Dependent Claim
19 words
A method as in claim 5 wherein said monitoring element includes an active layer capped with a protective layer.
Claim 8
Dependent Claim
12 words
A method as in claim 6 wherein said active layer comprises GaAs.
Claim 9
Dependent Claim
12 words
A method as in claim 7 wherein said active layer is undoped.
Claim 10
Dependent Claim
12 words
A method as in claim 7 wherein said active layer is doped.
Claim 11
Dependent Claim
25 words
A method as in claim 7 wherein said active layer is capped with a deposited protective layer comprising Al x Ga 1-x As, where 0.2<×<0.5.
Claim 12
Dependent Claim
23 words
A method as in claim 10 wherein said active layer is deposited on a layer comprising Al x Ga 1-x As, where 0.2<×<0.5.
Claim 13
Dependent Claim
25 words
A method as in claim 11 wherein said second-mentioned layer comprising Al x Ga 1-x As is deposited on a substrate layer that comprises GaAs.
Claim 14
Dependent Claim
38 words
A method as in claim 4 wherein control circuitry connected to the output of said detector is effective to provide a measure of the temperature in said chamber in the direct vicinity of the device being fabricated therein.
Claim 15
Dependent Claim
21 words
A method as in claim 13 wherein energization of a heating element contained within said chamber is controlled by said circuitry.
Claim 16
Dependent Claim
19 words
A method as in claim 13 wherein a process controller connected to said chamber is controlled by said circuitry.
Claim 17
Independent Claim
84 words
A method for in-situ measurement of temperature in an epitaxial growth gas phase or vacuum environment in a chamber, said method comprising the steps of optically exciting a sensing element positioned in said chamber to cause said element to emit photoluminescence, said element comprising III-V direct-bandgap semiconductor, spectrally resolving the intensity of the photoluminescence emitted by said element to provide a representation of the bandgap of said element, and processing said representation to obtain therefrom a measure of the temperature of said sensing element.
Claim 18
Independent Claim
84 words
A method for in-situ measurement of temperature in an epitaxial growth gas phase or vacuum environment in a chamber, said method comprising the steps of optically exciting a sensing element positioned in said chamber to cause said element to emit photoluminescence, said element comprising III-V direct-bandgap semiconductor, spectrally resolving the intensity of the photoluminescence emitted by said element to provide a representation of the bandgap of said element, and processing said representation to obtain therefrom a measure of the temperature of said sensing element.
Claim 19
Independent Claim
80 words
A method of measuring a parameter of a device in a gas phase or vacuum environment within a semiconductor growth processing chamber comprising the steps of positioning within said chamber a parameter monitoring element that comprises a III-V direct bandgap semiconductor, optically exciting said element to emit photoluminescence, and spectrally resolving the intensity of the photoluminescence emitted by said element to provide a measurement of the bandgap energy of said element and thereby also of the parameter of the device.
Claim 20
Independent Claim
80 words
A method of measuring a parameter of a device in a gas phase or vacuum environment within a semiconductor growth processing chamber comprising the steps of positioning within said chamber a parameter monitoring element that comprises a III-V direct bandgap semiconductor, optically exciting said element to emit photoluminescence, and spectrally resolving the intensity of the photoluminescence emitted by said element to provide a measurement of the bandgap energy of said element and thereby also of the parameter of the device.
Claim 21
Dependent Claim
50 words
A method as in claim 17 wherein the optical excitation of said element results from impingement thereon of laser energy and wherein the spectral resolution is carriers out by a monochromator and an intensity detector, the photoluminescense from said element impinging on said monochromator which then drives said intensity detector.
Claim 22
Dependent Claim
13 words
A method as in claim 18 wherein the parameter being measured is temperature.
References Cited (Backward Citations)
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