Granted Patent B2

US 7,169,717 · App. 10/536,788 · Granted Jan 30, 2007

Abstract

Claims (28)

1. A method of calibrating an RTP system, the method comprising:

providing at least two calibration wafers, wherein the calibration wafers have differing predetermined reflectivities;

successively subjecting each calibration wafer to a simulated thermal treatment comprising heat radiation;

determining the temperature of each calibration wafer during thermal treatment using a contact-based measuring device that is in contact with the wafer;

measuring radiation emitted from each calibration wafer during the simulated thermal treatment; and

calculating a set of temperature measurement model parameters to correct temperature measurements based on measured radiation by comparing temperature measurements based on measured radiation to the actual temperature determined using the contact-based measuring device.

2. The method as set forth in claim 1 , wherein the simulated thermal treatment comprises heating each calibration wafer to four different temperatures and holding the wafer at each temperature for a set period of time.

3. The method as set forth in claim 2 , wherein the four different temperatures lie in a range from about 200° C. to about 1200° C.

4. The method as set forth in claim 1 , wherein the calibration wafers comprise uncoated wafers doped to a transmissivity of about 0.0 to about 0.3 at the wavelength of the heat radiation.

5. The method as set forth in claim 4 , wherein each of the four calibration wafers have different reflectivites ranging from about 0.2 to about 0.8; a transmissivity of about 0.3; and a emissivity between about 0.25 and 0.8 at the wavelength of the heat radiation.

6. The method as set forth in claim 1 , wherein at least four calibration wafers are provided.

7. The method as set forth in claim 1 , wherein providing a calibration wafer comprises:

providing a wafer of semiconductor material;

subjecting the bulk material of the wafer to at least one of doping with foreign atoms and generating lattice defects to adjust the predetermined emissivity; and

coating the wafer to obtain a further optical characteristic.

8. A method according to claim 7 , wherein said further optical characteristic is a predetermined reflectivity.

9. A method according to claim 7 , wherein said emissivity is established to a value of between 0.25 and 0.8 at the wavelength of the heat radiation.

10. A method according to claim 7 , wherein said at least one of doping with foreign atoms and generating lattice defects is effected essentially homogenously over the bulk material of the wafer.

11. A method according to claim 7 , wherein said at least one of doping with foreign atoms and generating lattice defects is effected in a predetermined region.

12. A method according to claim 11 , wherein said predetermined region is a layer of the wafer.

13. A method according to claim 11 , wherein a surface layer of the wafer is doped.

14. A method according to claim 7 , wherein doping is effected with at least one of boron, phosphorous and arsenic.

15. A method according to claim 7 , wherein adjusting of the predetermined emissivity is effected essentially exclusively via said at least one of doping with foreign atoms and generating lattice defects.

16. A method according to claim 7 , wherein the wafer is doped with a density of foreign atoms that is between 10 16 and 10 19 foreign atoms per cubic centimeter.

17. A method according to claim 7 , wherein the predetermined emissivity is effected at least partially via a selection of the thickness of the wafer.

18. A method according to claim 7 , wherein said further optical characteristic is a reflectivity of the wafer, and wherein the reflectivity is established to a value between 0.2 and 0.8 at the wavelength of the heat radiation.

19. A method according to claim 7 , wherein the wafer is coated with a metallic layer to obtain the further optical characteristic.

20. A method according to claim 19 , wherein the wafer is coated with cobalt.

Assignments (7)