COVERAGE ANALYSIS OF A SULFUR-TERMINATED GAAS(001)-(2X6) SURFACE - THE EFFECT OF DOUBLE SULFUR-TREATMENT

Sulfur-terminated GaAs(001)-(2 x 6) surfaces have been investigated by photoelectron and Auger electron spectroscopy. Surface coverages of S and As are estimated from the angle dependence of electron emission t o evaluate the effect of double S-treatment, which is a preparation te chnique developed by Tsukamoto et al. It is found that a large amount of As remains on the surface after the first S-treatment and that a la rge portion of the residual As is replaced with S in the second S-trea tment. This fact explains the results of the scanning tunneling micros copy observation that the surface homogeneity is significantly improve d by the double S-treatment. (C) 1998 Elsevier Science B.V. All rights reserved.