LEC-growth and the major electrical and structural characteristics of semi-insulating gallium arsenide

Abstract

Etch-pit density, mobility, Hall constant and sheet resistance have been measured in several GaAs ingots grown by LEC procedure. The main results are that: i) the dislocation density is influenced by the melt stoichiometry; ii) the sheet resistance varies monotonically along the crystal radius; iii) the mobility and Hall constant vary with temperature and behave as if one deep level (which changed its filling state according to T) were present. Moreover, it has been observed that PBN crucibles chemically react with the molten boron oxide, resulting in a contamination of the melt, which can be responsible for crystal twinning.