Non-contact techniques for measuring temperature or radiation-heated objects

Claim 2

A non-contact method of determining a characteristic of a surface of an object, comprising the steps of: directing against said object surface incident electromagnetic radiation having a time varying component, wherein a portion of said incident radiation is reflected from said object surface with such a time varying component, detecting as a first signal a combined level of said reflected portion of the incident electromagnetic radiation and electromagnetic radiation that is emitted from said object surface, detecting as a second signal a level of the incident electromagnetic radiation that is being directed against said object surface, determining a magnitude of a time varying component in each of said first and second signals that is the result of said incident radiation time varying component, and combining at least the time varying component magnitudes of said first and second signals in a manner to obtain said object surface characteristic.

Claim 3

In a process of heating an object by directing electromagnetic radiation within a defined bandwidth against at least one surface of the object from lamps energized by alternating current, wherein an intensity of the lamp radiation includes a time varying component, a method of determining a thermal characteristic of said object surface, comprising the steps of: detecting as a first signal a combined level of radiation emitted from said object surface within a predetermined bandwidth and a portion of said lamp radiation within said predetermined bandwidth that is reflected from said object surface, said predetermined bandwidth overlapping said defined source bandwidth, detecting as a second signal a level of lamp radiation that is being directed within said defined bandwidth against said object surface, determining a magnitude of a time varying component in each of said first and second signals that is the result of said source time varying component, and combining at least the time varying component magnitudes of said first and second signals in a manner to obtain said object surface thermal characteristic.

Claim 4

In a process of heating an object by directing electromagnetic radiation within a defined bandwidth against at least one surface of the object from lamps energized by alternating current, wherein an intensity of the lamp radiation includes a time varying component, a method of determining a thermal characteristic of said object surface, comprising the steps of: detecting as a first signal a combined level of radiation emitted from said object surface within a predetermined bandwidth and a portion of said lamp radiation within said predetermined bandwidth that is reflected from said object surface, said predetermined bandwidth overlapping said defined source bandwidth, detecting as a second signal a level of lamp radiation that is being directed within said defined bandwidth against said object surface, determining a magnitude of a time varying component in each of said first and second signals that is the result of said source time varying component, and combining at least the time varying component magnitudes of said first and second signals in a manner to obtain said object surface thermal characteristic.

Claim 5

The method according to claim 1 wherein the combining step includes taking a ratio of the time varying component magnitudes of said first and second signals.

Claim 6

The method according to claim 1 wherein the surface characteristic being obtained is its reflectivity.

Claim 7

The method according to claim 2 wherein the combining step includes taking a ratio of the time varying component magnitudes of said first and second signals.

Claim 8

The method according to either of claim 3 or 5 wherein the combining step includes the further step of subtracting said ratio from one, thereby determining a quantity related to emissivity of the object surface.

Claim 15

The method according to claim 2 wherein the object includes a semiconductor wafer and the predetermined bandwidth includes a 0.95 micron wavelength.

Claim 16

The method according to claim 13 wherein the wafer is contained in a chamber having a substantially transparent wall through which the lamp radiation is passed from outside of the chamber.

Claim 17

The method according to claim 14 wherein the transparent wall includes quartz.

Claim 18

The method according to claim 14 wherein the detecting steps each includes positioning an end of a light pipe within the chamber between the transparent wall and the wafer in the path of the lamp radiation and extending the light pipe outside of the chamber to a photodetector.

Claim 19

The method according to claim 14 wherein the detecting steps each include positioning an end of a light pipe outside of the chamber between the transparent wall and the lamps in the path of the lamp radiation.

Claim 21

In a system for heating an article within a chamber having a substantially electromagnetic radiation of a given wall thereof by directing electromagnetic radiation of a given bandwidth through said window from outside of said chamber and against the object from a radiation source that also has a time varying intensity component, an improvement adapted to measure the temperature and/or emissivity of said article, comprising: first and second photodetectors, each of said photodetectors being characterized by generating an electrical signal proportional to a level of electromagnetic radiation incident thereon that includes said time varying intensity radiation component, means positioned with respect to the article for carrying to the first photodetector both a portion of source electromagnetic radiation reflected from said article surface area and electromagnetic radiation emitted by said article surface area within the bandwidth of the source electromagnetic radiation, thereby to generate a first electrical signal that contains a first time varying component, means positioned with respect to the source for carrying to the second photodetector a portion of source electromagnetic radiation substantially without any radiation reflected or emitted from said article surface, thereby to generate a second electrical signal that contains a second time varying component, and means receiving said first and second electrical signals for determining the temperature and/or emissivity of the object surface by at least combining magnitudes of the first and second electrical signal time varying components.

Claim 22

In a system for heating an article within a chamber having a substantially electromagnetic radiation of a given wall thereof by directing electromagnetic radiation of a given bandwidth through said window from outside of said chamber and against the object from a radiation source that also has a time varying intensity component, an improvement adapted to measure the temperature and/or emissivity of said article, comprising: first and second photodetectors, each of said photodetectors being characterized by generating an electrical signal proportional to a level of electromagnetic radiation incident thereon that includes said time varying intensity radiation component, means positioned with respect to the article for carrying to the first photodetector both a portion of source electromagnetic radiation reflected from said article surface area and electromagnetic radiation emitted by said article surface area within the bandwidth of the source electromagnetic radiation, thereby to generate a first electrical signal that contains a first time varying component, means positioned with respect to the source for carrying to the second photodetector a portion of source electromagnetic radiation substantially without any radiation reflected or emitted from said article surface, thereby to generate a second electrical signal that contains a second time varying component, and means receiving said first and second electrical signals for determining the temperature and/or emissivity of the object surface by at least combining magnitudes of the first and second electrical signal time varying components.

Claim 23

The system of claim 19 wherein said first and second photodetectors are positioned outside of said chamber, and wherein said first and second photodetector radiation carrying means include respective first and second light pipes that each have one end thereof positioned within said chamber.

Claim 24

The system of claim 19 wherein said first and second photodetector radiation carrying means include respective first and second light pipes that each have a light gathering end thereof positioned outside said chamber.

Claim 26

The system of claim 19 wherein said radiation source includes a lamp energized by alternating current electrical power having a given line frequency.

Claim 27

A non-contact method of measuring the emissivity of an object being heated by a plurality of lamps energized by an alternating current power source and having radiation therefrom directed against a surface of the object and having a wavelength range within a visible or near visible portion of the electromagnetic radiation spectrum, comprising the steps of: detecting a combined level of electromagnetic radiation emitted from said object surface within a defined radiation bandwidth that lies within said source radiation wavelength range and a portion of said source radiation that is reflected from said object surface, thereby to obtain a first signal proportional to a sum of a level of source radiation reflected from the object and a level of radiation emitted from the object, detecting a level of electromagnetic radiation within said defined bandwidth that is being directed against said object surface, thereby to obtain a second signal proportional to the level of source radiation being directed against the object surface, wherein said first and second signals each have a varying component, and combining said first and second signals by taking a ratio of an amplitude of the varying components of each of the first and second signals and subtracting from one, thereby to determine the emissivity of the heated object.

Claim 28

A non-contact method of measuring the emissivity of an object being heated by a plurality of lamps energized by an alternating current power source and having radiation therefrom directed against a surface of the object and having a wavelength range within a visible or near visible portion of the electromagnetic radiation spectrum, comprising the steps of: detecting a combined level of electromagnetic radiation emitted from said object surface within a defined radiation bandwidth that lies within said source radiation wavelength range and a portion of said source radiation that is reflected from said object surface, thereby to obtain a first signal proportional to a sum of a level of source radiation reflected from the object and a level of radiation emitted from the object, detecting a level of electromagnetic radiation within said defined bandwidth that is being directed against said object surface, thereby to obtain a second signal proportional to the level of source radiation being directed against the object surface, wherein said first and second signals each have a varying component, and combining said first and second signals by taking a ratio of an amplitude of the varying components of each of the first and second signals and subtracting from one, thereby to determine the emissivity of the heated object.

Claim 29

A non-contact method of measuring the temperature of an object being heated by a plurality of lamps energized by an alternating current power source and having radiation therefrom directed against a surface of the object and having a wavelength range within a visible of near visible portion of the electromagnetic radiation spectrum, comprising the steps of: detecting a combined level of electromagnetic radiation emitted from said object surface within a defined radiation bandwidth that lies within said source radiation wavelength range and a portion of said source radiation that is reflected from said object surface, thereby to obtain a first signal proportional to a sum of a level of source radiation reflected from the object and a level of radiation emitted from the object, detecting a level of electromagnetic radiation within said defined bandwidth that is being directed against said object surface, thereby to obtain a second signal proportion to the level of source radiation being directed against the object surface wherein said first and second signals each have a varying component, and combining said first and second signals by executing the following steps: taking a ratio of an amplitude of the varying components of each of the first and second signals, multiplying that ratio by a value of the second signal, thereby to determine an amount of the first signal that is due to reflected light, and subtracting said amount from said first signal, thereby determining a temperature dependent electromagnetic emission level from the object within said defined radiation bandwidth.

Claim 30

A non-contact method of measuring the temperature of an object being heated by a plurality of lamps energized by an alternating current power source and having radiation therefrom directed against a surface of the object and having a wavelength range within a visible of near visible portion of the electromagnetic radiation spectrum, comprising the steps of: detecting a combined level of electromagnetic radiation emitted from said object surface within a defined radiation bandwidth that lies within said source radiation wavelength range and a portion of said source radiation that is reflected from said object surface, thereby to obtain a first signal proportional to a sum of a level of source radiation reflected from the object and a level of radiation emitted from the object, detecting a level of electromagnetic radiation within said defined bandwidth that is being directed against said object surface, thereby to obtain a second signal proportion to the level of source radiation being directed against the object surface wherein said first and second signals each have a varying component, and combining said first and second signals by executing the following steps: taking a ratio of an amplitude of the varying components of each of the first and second signals, multiplying that ratio by a value of the second signal, thereby to determine an amount of the first signal that is due to reflected light, and subtracting said amount from said first signal, thereby determining a temperature dependent electromagnetic emission level from the object within said defined radiation bandwidth.

Claim 36

A non-contact method of measuring the temperature of a surface of an object, comprising the steps of: illuminating said object surface with optical radiation having a magnitude I L and a ripple component having a magnitude ΔI L , thereby to cause optical radiation to be reflected from the surface and combined with temperature dependent optical radiation emitted therefrom, said combined optical radiation having a magnitude I W and a ripple component having a magnitude ΔI W , detecting the magnitude and ripple component of the optical radiation being directed at said object surface, detecting the magnitude and ripple component of said combined optical radiation coming from the object surface, and combining said magnitude and ripple components substantially according to the following relationship: ##EQU4## thereby to measure the temperature of the object surface.

Claim 37

A non-contact method of measuring the temperature of a surface of an object, comprising the steps of: illuminating said object surface with optical radiation having a magnitude I L and a ripple component having a magnitude ΔI L , thereby to cause optical radiation to be reflected from the surface and combined with temperature dependent optical radiation emitted therefrom, said combined optical radiation having a magnitude I W and a ripple component having a magnitude ΔI W , detecting the magnitude and ripple component of the optical radiation being directed at said object surface, detecting the magnitude and ripple component of said combined optical radiation coming from the object surface, and combining said magnitude and ripple components substantially according to the following relationship: ##EQU4## thereby to measure the temperature of the object surface.

Claim 38

A non-contact method of measuring the emissivity of a surface of an object, comprising the steps of: illuminating said object surface with optical radiation having a ripple component with a magnitude ΔI L , thereby to cause optical radiation to be reflected from the surface and combined with optical radiation emitted therefrom, said combined optical radiation having a ripple component with a magnitude ΔI W , detecting the ripple component of the optical radiation being directed at said object surface, detecting the ripple component of said combined optical radiation coming from the object surface, and combining said ripple component substantially according to the following relationship: ##EQU5## thereby to measure the emissivity of the object surface.

Claim 39

A non-contact method of measuring the emissivity of a surface of an object, comprising the steps of: illuminating said object surface with optical radiation having a ripple component with a magnitude ΔI L , thereby to cause optical radiation to be reflected from the surface and combined with optical radiation emitted therefrom, said combined optical radiation having a ripple component with a magnitude ΔI W , detecting the ripple component of the optical radiation being directed at said object surface, detecting the ripple component of said combined optical radiation coming from the object surface, and combining said ripple component substantially according to the following relationship: ##EQU5## thereby to measure the emissivity of the object surface.