Temperature Control Method of Epitaxial Growth Apparatus

• US 20070062439A1
• Filed: 09/21/2006
• Published: 03/22/2007
• Est. Priority Date: 09/21/2005
• Status: Active Grant

• Current Assignee: Sumco Corporation
• Original Assignee: Sumco Corporation
• Inventors: Wada, Naoyuki, Kishi, Hiroyuki
• Granted Patent: US 7,833,348 B2
• Time in Patent Office: Days
• US Class Current: 117/89
• CPC Class Codes: C30B 25/10 Heating of the reaction chamber or the substrate
• CPC Class Codes: C30B 25/16 Controlling or regulating controlling or regulating in general G05

Abstract

An object of the invention is to calibrate an upper pyrometer for indirectly measuring a substrate temperature at the time of epitaxial growth in a comparatively short time and with accuracy to thereby improve the quality of an epitaxial substrate. After calibrating an upper pyrometer by a thermocouple mounted to a temperature calibrating susceptor, a measured value of a lower pyrometer is adjusted to a calibrated value of the upper pyrometer. Then, a correlation line between substrate temperature indirectly measured by the upper pyrometer at the time of epitaxial growth onto a sample substrate and haze of a sample substrate measured immediately after epitaxial growth is set to indirectly measure a substrate temperature by the upper pyrometer at the time of epitaxial growth onto a mass-production substrate. Moreover, substrate temperature at the time of epitaxial growth onto the mass-production substrate is estimated by applying the haze of the mass-production substrate measured immediately after epitaxial growth to the correlation line and then a measured temperature of the upper pyrometer is adjusted to the estimated temperature.

Claims

1. A method for controlling the temperature of an epitaxial growth apparatus having an upper pyrometer above a mass-production susceptor and a lower pyrometer below the mass-production susceptor to grow an epitaxial layer on a mass-production substrate mounted onto the susceptor based on the temperature readings of both the upper and lower pyrometers, comprising:

calibrating the upper pyrometer by a thermocouple mounted to a temperature calibrating susceptor previously set in place of the mass-production susceptor;

adjusting a measured value of the lower pyrometer to a calibrated value of the upper pyrometer;

setting a correlation line between a substrate temperature indirectly measured by the upper pyrometer at the time of epitaxial growth onto a sample substrate previously mounted onto the mass-production susceptor instead of the mass-production substrate and haze of a sample substrate measured immediately after epitaxial growth;

indirectly measuring a substrate temperature (Tx) by the upper pyrometer at the time of epitaxial growth onto the mass-production substrate;

estimating a substrate temperature (Ty) at the time of epitaxial growth onto the mass-production substrate by applying the haze of the mass-production substrate measured immediately after the epitaxial growth to the correlation line; and

performing a calibration for adjusting the measured temperature (Tx) of the upper pyrometer to the estimated temperature (Ty).

2. The method according to claim 1 wherein each of the haze of the sample substrate and the haze of the mass-production substrate are measured immediately after epitaxial growth by using a laser surface inspection apparatus.

3. The method according to claim 1, wherein the calibration for adjusting the temperature (Tx) of the mass-production substrate indirectly measured to the estimated temperature (Ty) of the mass-production substrate is carried out when the difference between the temperature (Tx) of the mass-production substrate at the time of epitaxial growth indirectly measured by the upper pyrometer and the temperature (Ty) of the mass-production substrate at the time of epitaxial growth estimated by applying the haze of the mass-production substrate to a correlation line becomes 5°

C. or higher.

4. An epitaxial substrate prepared using the controlling method of claim 1.

5. An epitaxial substrate prepared using the controlling method of claim 2.

6. An epitaxial substrate prepared using the controlling method of claim 3.