US5255286A — Multi-point pyrometry with real-time surface emis…

Claim 1

Independent Claim 163 words

A multi-point non-invasive, real-time pyrometry-based sensor apparatus for simultaneously measuring radiance of a semiconductor wafer in a fabrication reactor and compensating for wafer emissivity, comprising: a laser source for emitting a beam of light; a beam splitter module for receiving said beam, splitting said beam into a plurality of split beams, and simultaneously directing said split beams as incident beams to selected areas of the surface of the semiconductor wafer; circuitry means for receiving a plurality of reflected beams caused by reflection of said incident beams from said wafer and for receiving incoherent radiant energy emitted by the semiconductor wafer; circuitry means for detecting and processing said incident beams, said reflected beams and said incoherent radiant energy, for converting detected signals of said incident and reflected beams to values for semiconductor wafer emissivity and for converting said incoherent radiant energy into semiconductor wafer radiance measurements; and circuitry means for achieving real-time semiconductor wafer temperature measurements based on said emissivity values and radiance measurements.

Claim 2

Dependent Claim 163 words

A multi-point non-invasive, real-time pyrometry-based sensor apparatus for simultaneously measuring radiance of a semiconductor wafer in a fabrication reactor and compensating for wafer emissivity, comprising: a laser source for emitting a beam of light; a beam splitter module for receiving said beam, splitting said beam into a plurality of split beams, and simultaneously directing said split beams as incident beams to selected areas of the surface of the semiconductor wafer; circuitry means for receiving a plurality of reflected beams caused by reflection of said incident beams from said wafer and for receiving incoherent radiant energy emitted by the semiconductor wafer; circuitry means for detecting and processing said incident beams, said reflected beams and said incoherent radiant energy, for converting detected signals of said incident and reflected beams to values for semiconductor wafer emissivity and for converting said incoherent radiant energy into semiconductor wafer radiance measurements; and circuitry means for achieving real-time semiconductor wafer temperature measurements based on said emissivity values and radiance measurements.

Claim 3

Dependent Claim 40 words

The apparatus of claim 1, further comprising circuitry means for receiving a plurality of transmitted beams caused by said incident beams and wherein said detecting and processing circuitry means further comprises circuitry means for detecting and processing said transmitted beams.

Claim 4

Dependent Claim 15 words

The apparatus of claim 2, wherein said laser source generates a beam of infrared light.

Claim 5

Dependent Claim 20 words

The apparatus of claim 3, wherein said laser source generates a light beam having a wavelength of approximately 5.4 microns.

Claim 6

Dependent Claim 17 words

The apparatus of claim 2, wherein said detecting and processing circuitry means comprises a process control computer.

Claim 7

Dependent Claim 15 words

The apparatus of claim 1, wherein said laser source generates a chopped beam of light.

Claim 8

Dependent Claim 24 words

The apparatus of claim 6, wherein said chopped beam has a chopping frequency larger than a desired rate of real-time emissivity and temperature measurements.

Claim 9

Dependent Claim 52 words

The apparatus of claim 1, wherein said laser source and said beam splitter module associate with the fabrication reactor through a fiber-optic network, said fiber-optic network associated to receive said split means from said beam splitter and to direct said plurality of incident beams to said selected areas on the semiconductor wafer.

Claim 10

Dependent Claim 41 words

The apparatus of claim 8, further comprising a plurality of fiber-optic bundles associated to receive each of said incident beams from said fiber-optic network for directing and collimating said incident beams as said incident beams are directed to said semiconductor wafer.

Claim 11

Dependent Claim 49 words

The apparatus of claim 9, wherein the fabrication reactor comprises a wafer heating lamp module for directing optical energy toward the semiconductor wafer and said fiber-optic bundles are mounted within said lamp module for directing said incident beams in a direction perpendicular to the surface of said semiconductor wafer.

Claim 12

Dependent Claim 50 words

The apparatus of claim 1, wherein said beam and detecting and processing circuitry means further comprises a chopper multiplexer for receiving a plurality of independent signals representing said incident and reflected beams and said incoherent radiant energy and multiplexing said independent signals to produce a single time-division-multiplexed (TDM) output signal.

Claim 13

Dependent Claim 40 words

The apparatus of claim 10, wherein said detecting and processing circuitry means comprises an optical signal for detecting said independent signals and wherein said chopper multiplexer comprises a chopper wheel assembly for selectively directing said independent signals within said multiplexer.

Claim 14

Dependent Claim 21 words

The apparatus of claim 1 wherein said incoherent radiant energy is emitted from a plurality of points on said semiconductor wafer.

Claim 15

Dependent Claim 154 words

A real-time, non-invasive, in-situ sensor apparatus for temperature measurement of a heated semiconductor wafer, comprising: an electromagnetic energy source for simultaneously directing a plurality of incident coherent beams of electromagnetic energy to the surface of the semiconductor wafer; circuitry means for collecting a plurality of reflected coherent beams of electromagnetic energy resulting from the reflection of said plurality of incident coherent beams from the semiconductor wafer; circuitry means for collecting incoherent radiant energy emitted rom a plurality of points on said heated semiconductor wafer; circuitry means for calculating temperature values for the semiconductor wafer as a function of said plurality of incident and reflected coherent beams and said incoherent radiant energy; and circuitry means for measuring the surface roughness of the semiconductor wafer and for calculating emissivity and temperature values for the semiconductor wafer as a function of said plurality of incident and reflected coherent beams, said incoherent radiant energy, and said surface roughness.

Claim 16

Dependent Claim 154 words

A real-time, non-invasive, in-situ sensor apparatus for temperature measurement of a heated semiconductor wafer, comprising: an electromagnetic energy source for simultaneously directing a plurality of incident coherent beams of electromagnetic energy to the surface of the semiconductor wafer; circuitry means for collecting a plurality of reflected coherent beams of electromagnetic energy resulting from the reflection of said plurality of incident coherent beams from the semiconductor wafer; circuitry means for collecting incoherent radiant energy emitted rom a plurality of points on said heated semiconductor wafer; circuitry means for calculating temperature values for the semiconductor wafer as a function of said plurality of incident and reflected coherent beams and said incoherent radiant energy; and circuitry means for measuring the surface roughness of the semiconductor wafer and for calculating emissivity and temperature values for the semiconductor wafer as a function of said plurality of incident and reflected coherent beams, said incoherent radiant energy, and said surface roughness.

Claim 17

Dependent Claim 60 words

The apparatus of claim 14 further comprising circuitry means for associating each of said plurality of incident coherent beams with the corresponding reflected coherent beam, and further assisting each said incident coherent beam and said corresponding reflected coherent beam with said incoherent radiant energy to yield a temperature value for each of said plurality of points on said semiconductor wafer.

Claim 18

Dependent Claim 82 words

The apparatus of claim 14, wherein the semiconductor wafer resides within a semiconductor wafer fabrication reactor having a wafer heating lamp module for directly heating the semiconductor wafer and further comprising circuitry means for collecting said incident coherent beams, and wherein said circuitry means for collecting said incident coherent beams, said circuitry means for collecting said reflected coherent beams, and said circuitry means for collecting said incoherent radiant energy operate in real time as said heating lamp module heats the semiconductor wafer.

Claim 19

Dependent Claim 46 words

The apparatus of claim 16, wherein said incident and reflected coherent beam circuitry means respectively direct and collect said incident and reflected coherent beams and said incoherent radiant energy collecting circuitry means collects said incoherent radiant energy along a direction approximately perpendicular to the semiconductor wafer.

Claim 20

Independent Claim 134 words

A method for multi-point non-invasive, real-time pyrometry-based semiconductor wafer temperature measurement and simultaneously compensating for wafer emissivity effects, comprising: emitting a beam of optical energy; receiving said beam, splitting said beam into a plurality of split beams, and simultaneously directing said split beams as incident beams to selected areas of the surface of the semiconductor wafer; receiving a plurality of reflected beams caused by reflection of said incident beams from said wafer and receiving incoherent radiant energy from the semiconductor wafer; detecting and processing said incident beams, said reflected beams and said incoherent radiant energy and converting detections of said incident and reflected beams to values for semiconductor wafer emissivity and also converting detections of said incoherent radiant energy into semiconductor radiance values; and converting said radiance and emissivity values to wafer temperature measurements.

Claim 21

Independent Claim 134 words

A method for multi-point non-invasive, real-time pyrometry-based semiconductor wafer temperature measurement and simultaneously compensating for wafer emissivity effects, comprising: emitting a beam of optical energy; receiving said beam, splitting said beam into a plurality of split beams, and simultaneously directing said split beams as incident beams to selected areas of the surface of the semiconductor wafer; receiving a plurality of reflected beams caused by reflection of said incident beams from said wafer and receiving incoherent radiant energy from the semiconductor wafer; detecting and processing said incident beams, said reflected beams and said incoherent radiant energy and converting detections of said incident and reflected beams to values for semiconductor wafer emissivity and also converting detections of said incoherent radiant energy into semiconductor radiance values; and converting said radiance and emissivity values to wafer temperature measurements.

Claim 22

Dependent Claim 28 words

The method of claim 18, further comprising he steps of receiving a plurality of transmitted beams caused by said incident beams and detecting and processing said transmitted beams.

Claim 23

Dependent Claim 22 words

The method of claim 19, wherein said beam emitting step further comprises the step of generating a beam of infrared optical energy.

Claim 24

Dependent Claim 21 words

The method of claim 10, wherein said infrared optical energy comprises a laser beam having a wavelength of approximately 5.4 microns.

Claim 25

Dependent Claim 21 words

The method of claim 18, wherein said step of emitting a beam further comprises emitting a chopped beam of optical energy.

Claim 26

Dependent Claim 26 words

The method of claim 22, wherein said chopped beam has a chopping frequency that is larger than a desired rate of real-time temperature and emissivity measurement.

Claim 27

Dependent Claim 55 words

The method of claim 18, further comprising the step of associating a laser and a beam splitter with a fabrication reactor through a fiber-optic network, said beam splitter generating said split beams, and associating said fiber-optic network to receive said split beams from said beam splitter and direct said incident beams to the semiconductor wafer.

Claim 28

Dependent Claim 42 words

The method of claim 24, further comprising the step of associating a plurality of fiber-optic bundles to receive each of said incident beams from said fiber-optic network for collimating said incident beams as said incident beams are directed to said semiconductor wafer.

Claim 29

Dependent Claim 48 words

The method of claim 25, wherein the fabrication reactor comprises a heating lamp module for directing optical energy toward the semiconductor wafer and said fiber-optic bundles ar mounted within said lamp module for directing said incident beams in a direction approximately perpendicular to the said semiconductor wafer surface.

Claim 30

Dependent Claim 51 words

The method of claim 18, wherein said step of detecting and processing further comprises the steps of receiving a plurality of independent signals representing said incident and reflected beams and said incoherent radiant energy and time-division-multiplexing said signals to produce a single time-division-multiplexed output signal from said plurality of received signals.

Claim 31

Dependent Claim 45 words

The method of claim 27, wherein said step of detecting and processing is performed with an optical signal detector for detecting said independent signals and a chopper multiplexer which comprises a chopper wheel assembly for selectively and periodically directing said independent signals within said multiplexer.

Claim 32

Dependent Claim 17 words

The method of claim 18, wherein said step of processing is performed with a process control computer.

Claim 33

Dependent Claim 28 words

The method of claim 18 wherein the step of receiving incoherent radiant energy comprises the step of collecting emitted energy from a plurality on points on the wafer.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1996-10-18	1997-04-19	1997-10-19	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2000-10-18	2001-04-19	2001-10-19	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2004-10-18	2005-04-19	2005-10-19	$7700.00	Window Closed / Lapsed

Multi-point pyrometry with real-time surface emissivity compensation

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