The gettering of defects and impurities in GaAs by using heat treatment of Y-coated wafers was investigated. The gettering was shown to be of volume type. That permitted high-resistivity material to be obtained which exhibited a near-uniform distribution of electron concentration and minority carrier lifetime in wafers with thicknesses of up to 1.6mm.

Distribution of Defects and Impurities in Gallium Arsenide Wafers after Surface Gettering. A.T.Gorelenok, V.F.Andrievskii, A.V.Kamanin, S.I.Kohanovskii, N.M.Shmidt: Nuclear Instruments and Methods in Physics Research B, 2002, 186[1-4], 240-5