Topographic changes and surface contact potential variations near to defects on the surfaces of double heterojunction structures, on Ge substrates, were studied by using scanning force microscopy and electrostatic force microscopy. A comparison with transmission electron microscopic results indicated that the surface defects were directly related to stacking faults which originated at the GaAs/Ge interface. The surface contact potential inhomogeneities near to these defects were consistent with variations in the Si dopant concentration.

Topographic and Electronic Studies of Wedge-Shape Surface Defects on AlGaAs/GaAs Films Grown on Ge Substrates Q.Xu, J.W.P.Hsu, J.A.Carlin, R.M.Sieg, J.J.Boeckl, S.A.Ringel: Applied Physics Letters, 1999, 75[14], 2111-3