Radiometric temperature measurement system
AssigneeExactus, Inc.
InventorsRonald A. Palfenier, Patrick J. Nystrom
Life of this patent
Estimating the term…
Abstract
A radiometric system (10) typically used in semiconductor wafer processing has reduced optical losses, improved wavelength selectivity, improved signal to noise, and improved signal processing to achieve wafer temperature measurements from about 10° C. to 4,000° C. A YAG rod collection optic (12) directly couples specimen radiation (14) to a filter (18) and photo detector (20). The filter determines which radiation wavelengths are measured, and optionally includes a hot/cold mirror surface (22) for reflecting undesired radiation wavelengths back to the specimen. The detector is formed from doped GaAlAs having a peaked response near 900 nm. A signal processor (28) converts the signal into a temperature reading.
Claims27
A radiometric temperature measurement system that performs a measurement of a temperature of a target medium, comprising:
- a light guide formed of a material including yttrium aluminum garnet (YAG), the light guide configured for collection of radiation emitted by the target medium, the radiation collected having an intensity and occupying a range of wavelengths representing the temperature of the target medium;
- a radiation detector receiving the radiation collected by the light guide to provide a signal that is indicative of the temperature of the target medium;
- and
- an electronic circuit that processes the signal to provide the temperature measurement, the electronic circuit including an analog-to-digital converter (ADC) with an auto-ranging capability that adjusts an integration time of the ADC to maintain an output that is substantially centered between a minimum value and a maximum value.
A radiometric temperature measurement system that performs with low temperature measurement sensitivity noncontacting measurement of a temperature of a target medium, comprising:
- a radiation emission collector including a probe element configured for noncontacting collection of radiation emitted by the target medium, the radiation collected by the probe element having an intensity and occupying a range of wavelengths representing the temperature of the target medium;
- a radiation detector receiving a portion of the radiation collected by the probe element, the radiation emission collector directly coupled to the radiation detector to provide to it low loss transmission of the portion of the radiation collected, the radiation detector having a narrowband wavelength selective spectral response characteristic that enables the radiation detector in response to wavelengths of radiation within the range of wavelengths to provide a signal that is indicative of the temperature of the target medium;
- and
- an integrating converter that is responsive to the signal provided by the radiation detector, the signal having a signal amplitude that is indicative of the temperature of the target medium, and the integrating converter providing after each of successive integration intervals a sample output signal corresponding to the signal amplitude, the successive integration intervals occurring in a timing sequence in the absence of timing jitter caused by interruption of any one of the successive integration intervals.
A radiometric temperature measurement system that performs with low temperature measurement sensitivity noncontacting measurement of a temperature of a target medium, comprising:
- a radiation emission collector including a probe element configured for noncontacting collection of radiation emitted by the target medium, the radiation collected by the probe element having an intensity and occupying a range of wavelengths representing the temperature of the target medium;
- a radiation detector receiving a portion of the radiation collected by the probe element, the radiation emission collector directly coupled to the radiation detector to provide to it low loss transmission of the portion of the radiation collected, the radiation detector having a narrowband wavelength selective spectral response characteristic that enables the radiation detector in response to wavelengths of radiation within the range of wavelengths to provide a signal that is indicative of the temperature of the target medium;
- and
- an electronic circuit that processes the signal to provide a temperature measurement, the electronic circuit including an analog-to-digital converter (ADC) with an auto-ranging capability that adjusts an integration time of the ADC to maintain an output that is substantially centered between a minimum value and a maximum value.
A radiometric temperature measurement system that performs with low temperature measurement sensitivity noncontacting measurement of a temperature of a target medium, comprising:
- a radiation emission collector including a probe element configured for noncontacting collection of radiation emitted by the target medium, the radiation collected by the probe element having an intensity and occupying a range of wavelengths representing the temperature of the target medium;
- and
- a radiation detector receiving a portion of the radiation collected by the probe element, the radiation emission collector directly coupled to the radiation detector to provide to it low loss transmission of the portion of the radiation collected, the radiation detector having a narrowband wavelength selective spectral response characteristic that enables the radiation detector in response to wavelengths of radiation within the range of wavelengths to provide a signal that is indicative of the temperature of the target medium, the radiation detector further having a field of view (FOV);
- and
- the measurement system further having a zero offset calibration level that is below the low temperature measurement sensitivity of the measurement system, the zero offset calibration level being determined by providing a target medium having an emissivity greater than about 0.8, cooling the target medium, configuring the radiation detector so that the cooled target medium occupies the full FOV, and measuring the temperature of the cooled target medium.
Dependencies are inferred from the claim text.