Method and apparatus for infrared pyrometer calibration in a thermal processing system

• US 5,762,419 A
• Filed: 03/28/1996
• Issued: 06/09/1998
• Est. Priority Date: 07/26/1995
• Status: Expired due to Term

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Yam, Mark
• Primary Examiner(s): GUTIERREZ, DIEGO F
• Application Number:
  US08/623,433
• Time in Patent Office: 803 Days
• Field of Search: 374/2, 374/131, 250/252.1
• US Class Current: 374/2
• CPC Class Codes: G01J 5/0003 for sensing the radiant heat transfer of samples, e.g. emittance meter
• CPC Class Codes: G01J 5/52 using comparison with reference sources, e.g. disappearing-filament pyrometer
• CPC Class Codes: G01J 5/53 Reference sources, e.g. standard lamps; Black bodies
• CPC Class Codes: G01J 5/80 Calibration using comparison with reference sources G01J5/52

Abstract

A calibration instrument for calibrating a temperature probe, such as pyrometer, uses a stable light source and a filter to simulate a blackbody of a known temperature. An alignment tool aligns a light-emitting surface of the calibration instrument to the input of the temperature probe. The calibration instrument may include a fiber optic bundle to transmit light from the light source to the light emitting surface.

Claims

1. An apparatus for calibrating a temperature probe for a thermal processing chamber, comprising:

a) a light source optically coupled to a surface to emit light of a predetermined intensity through said surface during calibration;

b) a filter positioned between said light source and said surface to cause the radiation spectrum emitted from said surface over a predetermined wavelength range to more closely approximate the radiation spectrum of a black body of a predetermined temperature over said predetermined wavelength range; and

c) an alignment mechanism for aligning said surface with an input end of said temperature probe.

2. The apparatus of claim 1 wherein said light source comprises a light emitting diode (LED).

3. The apparatus of claim 1 wherein said predetermined wavelength range is in the infrared.

4. The apparatus of claim 1 wherein said predetermined wavelength range is approximately 0.80 to 0.94 microns.

5. The apparatus of claim 1 further comprising an indicia indicating the predetermined temperature approximated by said surface.

6. The apparatus of claim 1 further comprising a lighting fixture having a cavity, and said light source is positioned in said cavity.

7. The apparatus of claim 6 wherein said filter is positioned in said cavity.

8. The apparatus of claim 6 wherein said surface comprises an aperture in said lighting fixture.

9. The apparatus of claim 6 further comprising a fiber optic guide, and wherein said light source is optically coupled to a first end of said fiber optic guide and said surface comprises a second end of said fiber optic guide.

10. A method of calibrating a temperature probe that measures a temperature of a substrate for a thermal processing chamber, comprising:

a) generating light of a stable intensity from a light source;

b) directing said light to a surface to emit light of a predetermined intensity from said surface during calibration;

c) filtering said light with a filter positioned between said light source and said surface to cause the radiation spectrum emitted from said surface over a predetermined wavelength range to more closely approximate the radiation spectrum of a black body of a predetermined temperature over said predetermined wavelength range; and

c) aligning said surface with an input end of said temperature probe.

11. An apparatus for calibrating a temperature probe for a thermal processing chamber, comprising:

a) a light source optically coupled to an aperture to emit light of a predetermined intensity through said aperture during calibration;

b) a filter positioned between said light source and said aperture to cause the radiation spectrum emitted from said aperture over a predetermined wavelength range to more closely approximate the radiation spectrum of a black body of a predetermined temperature over said predetermined wavelength range; and

c) an alignment mechanism for aligning said aperture with an input end of said temperature probe.