METHOD OF GROWTH OF GAAS CRYSTAL HAVING SEMIINSULATING PROPERTY

摘要

PURPOSE:To obtain the same free electron concentration even by applying the same injection condition to all substrates cut out from ingot crystal, by adding C and O to a raw material intentionally, growing GaAs ingot crystal. CONSTITUTION:In growing GaAs ingot crystal, C and O are intentionally added to a raw material, to grow GaAs ingot crystal. For example, the top of the melt 21 consisting of Ga, As, C and Ga2O3 is sealed with a liquid sealing material of B2O3 in the crucible 23 of thermally synthesized boron nitride. As the melt 21 is heated to =1,250 deg.C by the RF coil 27 in a Kr gas atmosphere at 20kg/cm2, the GaAs ingot crystal 25 is pulled up by an ordinary crystal growth method. In the operation, amounts of C and Ga2O3 added in molar ratios to GaAs are 10-7 and 2X10-5, respectively. The titled crystal having extremely small change in C concentration in the direction of ingot crystal growth, capable of providing easily the same free electron concentration even by applying the same injection condition to all substrates cut out from the ingot crystal, is grown.