Dependence of electrical properties on the crystallographic orientation of CBr4-doped GaAs epilayers grown on GaAs substrates by atmospheric pressure metalorganic chemical vapor deposition

Abstract

Carbon incorporation into GaAs epilayers has been performed by atmospheric pressure metalorganic chemical vapor deposition using CBr4. The electrical properties of CBr4-doped GaAs epilayers grown on the GaAs substrates with various surface crystallographic orientations between (100) and (111)A were investigated. The electrical properties of the epilayers showed a strong crystallographic orientation dependence. On increasing the surface offset angle, the hole concentration of CBr4-doped GaAs epilayers rapidly decreased with a hump at (311)A. The lower hole concentration at the high offset angle can be explained by its higher desorption rate than that of the (100) surface. This hole concentration dependence on the offset angle was not changed in spite of the growth temperature and the V/III ratio variation given in this work. The above behaviors indicate that the surface kinetics plays an important role in the C incorporation into the non-planar GaAs epilayers. (C) 1997 Elsevier Science Ltd.