SUBSTRATE ORIENTATION EFFECT ON ZN DELTA-DOPING IN GAAS GROWN BY METAL-ORGANIC VAPOR-PHASE EPITAXY

The substrate orientation dependence of Zn incorporation on the nongro wing surface in the AsH3 containing ambient was investigated using Zn delta-doped layers in GaAs grown by metal organic vapour-phase epitaxy (MOVPE). We found that the Zn delta-doping concentration significantl y decreases with an increase of the (1 0 0) off-angle towards (1 1 1)B along the [0 1 (1) over bar] direction. The Zn incorporation on the n ongrowing As-terminated (1 1 1)B surface is negligible. A notable incr ease of the Zn incorporation was observed with increasing the (1 0 0) off-angle towards (1 1 1)A, while the maximum Zn delta-doping concentr ation was obtained on the (3 1 1)A surface. The Zn density decreases w ith a further increase in the (1 0 0) off-angle towards (1 1 1)A after (3 1 1)A. Based on the bonding configurations of the nongrowing surfa ce, the possible mechanism of orientation effect on Zn incorporation i s discussed. (C) 1998 Elsevier Science B.V. All rights reserved.