Methods and a device for measuring melt surface temperature within apparatus for pulling a single crystal

Abstract

In a conventional method, it is difficult to reject a stray light component with certainty, so that it is difficult to accurately measure the temperature of the melt surface. Since a temperature measuring device and a computing means are expensive, the cost of the measurement tends to be high. Modifications to an existing apparatus for pulling a single crystal are required, which is an inconvenience. In order to solve the above problems, a CCD camera is used for detecting the radiation light luminance distribution of the melt surface, the minimum radiation light luminance Lmin is determined based on the radiation light luminance distribution data measured using the CCD camera, and the temperature TS of the melt surface within an apparatus for pulling a single crystal is computed based on the minimum radiation light luminance Lmin.

Dependencies are inferred from the claim text.