Temperature control method of epitaxial growth apparatus

• US 7,833,348 B2
• Filed: 09/21/2006
• Issued: 11/16/2010
• Est. Priority Date: 09/21/2005
• Status: Active Grant

• Current Assignee: Sumco Corporation
• Original Assignee: Sumco Corporation
• Inventors: Wada, Naoyuki, Kishi, Hiroyuki
• Primary Examiner(s): Komakov; Michael
• Assistant Examiner(s): RAO, G NAGESH
• Application Number:
  US11/533,889
• Publication Number:
  US 20070062439A1
• Time in Patent Office: 1,517 Days
• Field of Search: 117/14, 117/89, 117/94, 117/106, 117/201, 117/222, 118/715, 118/719, 118/724
• 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:

performing a first calibration for 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 temperature of a sample substrate indirectly measured by the upper pyrometer at the time of epitaxial growth onto the sample substrate previously mounted onto the mass-production susceptor instead of the mass-production substrate and haze of the sample substrate measured immediately after epitaxial growth;

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

estimating a temperature (Ty) of the mass production substrate 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 second calibration for adjusting the measured temperature (Tx) of the upper pyrometer to the estimated temperature (Ty) of the mass production substrate.

2. The method according to claim 1 wherein each of the haze of the sample substrate and the haze of the mass-production substrate is 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.