Method and apparatus for measuring a diameter of a single crystal

Abstract

The invention relates to method and apparatus for measuring a diameter of a single crystal wherein growth portions including a shoulder portion and the following can be accurately measured with respect to their diameter. The method for the measurement includes the steps of causing an oscillation center of a single crystal being grown according to the Czochralski method while oscillating and a scanning line of a one-dimensional CCD camera to coincide with each other, and deciding a diameter of the single crystal from all the images measured with the one-dimensional CCD camera over a measuring time which is longer than an oscillation cycle of the single crystal. The apparatus includes a one-dimensional CCD camera, an XY table capable of moving the one-dimensional CCD camera in horizontal and vertical directions, an apparatus for deciding a scanning position, at which an image of a growth portion of a single crystal is measured, from image signals from the one-dimensional CCD camera, and an apparatus for calculating a diameter of the single crystal based on the image signals from the one-dimensional CCD camera scanning at the scanning position. According to the method and apparatus the invention for measuring a diameter of a single crystal, a diameter of the single crystal being grown can be precisely measured, thereby ensuring an appropriate control of the diameter of the single crystal automatically without resorting to hands (or without resorting to manual operations). Moreover, a demand for single crystals with a large size and a heavy weight can be met, and the growth of a single crystal can be made efficiently.

Dependencies are inferred from the claim text.