Defect classifying method and optical inspection apparatus for silicon carbide substrate

摘要

Provided are a defect classifying method and an inspection apparatus which are capable of classifying a defect by distinguishing a basal plane dislocation, which is a killer defect in bipolar high-voltage elements, from other defects. The defect classifying method according to the present invention includes: projecting an illumination beam toward a silicon carbide substrate and forming a reflection image and a photoluminescence image; a first inspection step of detecting a defect image from the reflection image formed; a second inspection step of detecting a defect image from the photoluminescence image formed; and a defect classification step of classifying detected defects based on whether or not the defect image is detected and the shape of the detected defect image.

主权项

1. A defect classifying method that detects a defect which is present at a silicon carbide substrate and classifies the defect by distinguishing a basal plane dislocation from other crystal defects, the defect classifying method comprising:
projecting an illumination beam toward the silicon carbide substrate and scanning the silicon carbide substrate with the illumination beam; condensing reflected light and photoluminescence light emitted from the silicon carbide substrate; separating, from the condensed light, each of reflected light and photoluminescence light of a visible region or an infrared region, and detecting each of the reflected light and the photoluminescence light of the visible region or the infrared region; a first inspection step of detecting a defect from the detected reflected light and detecting a defect image of the reflected light; a second inspection step of detecting a defect from the detected photoluminescence light and detecting a defect image of the photoluminescence light; and a defect classification step of classifying each defect detected in the first and second inspection steps, wherein when the defect image of the photoluminescence light is detected in the second inspection step, the defect is classified with reference to a result of a reflected light inspection in the first inspection step.