Thermal processing apparatus and thermal processing method through light irradiation

Abstract

A substrate in a chamber is preheated through light irradiation by a halogen lamp and then heated through irradiation with flash light from a flash lamp. Ammonia is supplied to the chamber from an ammonia supply mechanism to form ammonia atmosphere. The temperature of the substrate at heating processing is measured by a radiation thermometer. When the measurement wavelength band of the radiation thermometer overlaps with the absorption wavelength band of ammonia, the set emissivity of the radiation thermometer is changed and set to be lower than the actual emissivity of the substrate. When radiation light emitted from the substrate is absorbed by the ammonia atmosphere, the radiation thermometer can accurately output the temperature of the substrate as a measured value by reducing the set emissivity of the radiation thermometer.

Description

BACKGROUND OF THE INVENTION[0001]Field of the Invention[0002]The present invention relates to a thermal processing apparatus and a thermal processing method that heat a thin-plate fine electronic substrate (hereinafter simply referred to as a “substrate”) such as a semiconductor wafer by irradiating the substrate with light.[0003]Description of the Background Art[0004]In a process of manufacturing a semiconductor device, flash lamp annealing (FLA) that heats a semiconductor wafer in an extremely short time has attracted attention. The flash lamp annealing is a thermal processing technology of rising temperature only at the surface of a semiconductor wafer in an extremely short time (several milliseconds or less) by irradiating the surface of the semiconductor wafer with flash light using a xenon flash lamp (hereinafter, a simple notation of “flash lamp” means the xenon flash lamp).[0005]The xenon flash lamp has an emission spectral distribution ranging from ultraviolet to near-infra...

AI Technical Summary

Benefits of technology

This patent aims to accurately measure the temperature of a substrate when the intensity of radiation light from it is reduced through absorption by the processing gas. This is important for ensuring precise control over the substrate's temperature during processing. The technical effect is to provide a reliable and accurate means of measuring substrate temperature in a processing gas that absorbs infrared light.

Problems solved by technology

However, when thermal processing of a semiconductor wafer is performed in ammonia atmosphere, temperature measurement by a radiation thermometer is encumbered by ammonia.

Thus, when the measurement result is lower than the actual wafer temperature, the output of the lamp becomes excessive and the semiconductor wafer is heated to a temperature higher than a target temperature.

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