Method for measuring the orientation of a single crystal substrate composed of uniaxial crystals

摘要

PROBLEM TO BE SOLVED: To provide a method by which a plane orientation of a single crystal substrate comprising a uniaxial crystal can be accurately and easily measured by an optical process without using an X-ray diffraction method, and the plane orientation can be measured without restrictions in thickness of the substrate or plane orientations thereof.SOLUTION: A method for measuring a plane orientation of a single crystal substrate comprising a uniaxial crystal is provided, using such a property that when light in a given direction is made to be incident to the single crystal substrate comprising a uniaxial crystal, a refractive index for the light is a synthesized value of refractive indices specific to the crystal main axis and is turned to be a function of an incident direction of the light. The method is carried out through two separated steps of measurement: a step of measuring an inclination orientation of the crystal main axis to the original flat orientation of the substrate; and a step of measuring an inclination angle of the crystal main axis with respect to the normal direction of the substrate.