GALLIUM ARSENIDE CRYSTAL OF LOW DEFECT DENSITY AND SEMIIINSULATION

摘要

PURPOSE:To obtain the large-sized crystal of which the defect such as dislocation is reduced and which has an improved quality by a method wherein the gallium arsenide crystal containing deep acceptor impurity excessively as compared with shallow donor impurity is made to contain specific boron of which the density of oxygen is less than a specified value. CONSTITUTION:The gallium arsenide crystal of semi-insulation containing the deep acceptor impurity such as chromium and vanadium excessively in density compared with the shallow donor impurity such as silicon and having specific electric resistance of 106OMEGAcm or more in 300 deg.K is made to contain the boron of 1.2X1017- 1.2X1018cm-3 and, in addition, the density of oxygen thereof is set at 2X1018cm-3 or less. By this method, the large-sized gallium arsenide crystal having the diameter of 50mm. or more and little crystal defect such as dislocation and deposits can be obtained.