PURPOSE: To enable measurement of a crystal defect with a high throughput by providing a photosensor having a light-sensing surface being perpendicular to the direction of bending reflection which is different from the direction of regular reflection of a light beam on a complete specular surface and specific to a section gradient of the defect.
CONSTITUTION: A scanning direction 9 of a laser beam being parallel to the orientation flat 6 of an Si wafer is made the direction of the axis X, while the direction of an oxidation-induced defect 5 being perpendicular to the orientation flat 6 is made the direction of the axis Y. On the occasion when beam scanning is executed in the direction of the axis X in which the defect 5 exists, an angle of incidence of an incident light 7 is made θi. When the beam is cast on the defect 5 it is bent by an angle 2θ to the direction of the axis Y by a gradient θ (which is a section gradient of a crystal transformation defect and has uniformity) and reflected. By disposing light-sensing parts 10a and 10b on extensions of reflected lights 8a and 8b deviating by angles ±2θ from a plane Y-Z in respect to an angle θi of reflection on this plane, so that the light-sensing surfaces thereof are positioned perpendicularly thereto, only the reflected lights by the defect 5 can be sensed. As to a diffusedly reflected light by a particle or the like, it is advisable to provide a large light-sensing part additionally for receiving it.
| JPH03276049 | OPTICAL HEAD FOR OPTICAL SURFACE INSPECTING MACHINE |
| JPS6273140 | CRYSTAL EVALUATING APPARATUS |
SEKIGUCHI SHINGO
NISHIKAWA MASAMITSU
NOZAWA MASAHITO
