METHODS FOR MEASURING AND CONTROLLING DISTANCE BETWEEN LOWER END SURFACE OF HEAT-BLOCKING MEMBER AND SURFACE OF STARTING MATERIAL MELT, AND METHOD FOR MANUFACTURING SILICON SINGLE CRYSTAL

摘要

Disclosed is a method in which when a silicon single crystal is pulled up while a magnetic field is being applied to a starting material melt in a crucible by the Czochralski method, a reference reflector is provided in a heat-blocking member located above the surface of the starting material melt and the distance between the lower end surface of the heat-blocking member and the surface of the starting material melt is measured. Said method for measuring the distance between the lower end surface of the heat-blocking member and the surface of the starting material melt is characterized in that the reference reflector is provided inside a recessed portion provided in the lower end surface of the heat-blocking member, the distance between the lower end surface of the heat-blocking member and the surface of the starting material melt is actually measured, the position of a mirror image of the reference reflector reflected by the surface of the starting material melt is observed by a fixed point observation instrument, the movement distance of the mirror image is measured by the fixed point observation instrument while the silicon single crystal is being pulled up, and the distance between the lower end surface of the heat-blocking member and the surface of the starting material melt is calculated from the actually measured value and the movement distance of the mirror image. Consequently, the method for measuring the distance between the lower end surface of the heat-blocking member and the surface of the starting material melt, by which the distance between the lower end surface of the heat-blocking member and the surface of the starting material melt can be stably and more accurately measured, is provided.