JPS6451614A - Diagnostic device in recrystallizing device - Google Patents

Abstract

PURPOSE:To prevent the generation of a crystal defect resulting from the state of the surface of a semiconductor layer by irradiating the peripheral section of the position of irradiation of high energy beams in the semiconductor layer with beams for decision, detecting beams for decision reflected to the semiconductor layer and providing a means deciding the state of the semiconductor layer on the basis of the detection. CONSTITUTION:When a wafer 3 having a stepped section in the lower layer of a polycrystalline silicon thin-film is recrystallized, the intensity of the reflected beams of non-recrystallized region evaluating beams La detected by a non-crystallized region evaluating beam photodetector 6 is weakened at the front position of a position where the stepped section of the wafer 3 is irradiated with recrystallizing beams Lr. A controller 10 detects the weakening of the reflected beams, and detects the presence of the stepped section. The presence of the stepped section is detected, a driver circuit 11 is controlled at timing when the time when a space Wa between the position of irradiation of recrystallizing beams Lr and the position of irradiation of non-recrystallized region evaluating beams La is scanned passes, and the intensity of recrystallizing beams Lr is intensified. Accordingly, the wafer 3 is recrystallized by intensified recrystallizing beams Lr, thus preventing the nonuniformity of a temperature rise due to the stepped section of a lower layer in the wafer 3.