PROCEDURE CHECKING DIAMETER OF SILICON MONOCRYSTAL GROWN FROM MELT Russian patent published in 2002 - IPC

FIELD: production of semiconductors. SUBSTANCE: optical axis of sensor in furnace is arranged at angle of 5-20 degrees with plane passing through axis of grown crystal. Comparison monocrystal is grown. Position of radiation from meniscus of column of melt in under-crystal region of seed Y_o = 11,5 mm. Position of radiation from meniscus of column of melt corresponding to moment of hitting its cylindrical part Y_c = 42 mm. Diameter of cylindrical part of comparison monocrystal D_c = 153 mm, specified diameter of cylindrical part of grown monocrystal D_sp = 153 mm. Moment of hitting of cylindrical part is found by formula and monocrystal with specified diameter of cylindrical part is grown. To obtain it crucible with melt is moved , radiation from meniscus of seed of grown monocrystal is set equal to 11.5 mm. Sensitive element is moved along carriage of optical sensor and is set in position 42 mm. Cylindrical part of grown monocrystal is hit when radiation of meniscus of column of melt reaches established position of sensitive element of optical sensor. Maximum deviation from specified diameter along length of cylindrical part of monocrystal ±2,0 mm. EFFECT: increased output of good products, decreased number of rejects. 4 cl