Patent ID: 6056817
Filing Date: 2000-05-02
Classification: C30B

Abstract:
A process for producing a semi-insulating InP single crystal having a uniformity of mobility not more than 10% in the single crystal and a uniformity of resistivity not more than 20% in the single crystal, comprising:a first step heat-treatment for heating an undoped InP single crystal having a concentration of a residual impurity of not more than 0.05 ppmw containing at least one of Fe, Co and Cr, at a temperature of not less than 930.degree. C. and less than 1000.degree. C. in an atmosphere of phosphorous vapor pressure in the ampoule which is not less than 1 atm and less than 5 atm in order to semi-insulate the InP single crystal; anda second step heat-treatment for thereafter heating the InP single crystal at a temperature of not less than 662.degree. C. and less than 900.degree. C. in an atmosphere of phosphorous vapor pressure in the ampoule which is not less than 5 atm nor more than 50 atm in order to improve a uniformity of electrical properties in the InP single crystal.