DEPENDENCE OF CARBON INCORPORATION ON CRYSTALLOGRAPHIC ORIENTATION OFGAAS AND ALGAAS GROWN BY METALORGANIC CHEMICAL-VAPOR-DEPOSITION USINGCBR4

The electrical properties of CBr4-doped GaAs and Al0.3Ga0.7As epilayer s grown on GaAs substrates with various surface crystallographic orien tations from (100) toward (111)A were investigated. Carbon incorporati on into GaAs and AlGaAs epilayers was performed by atmospheric pressur e metalorganic chemical vapor deposition using CBr4. The electrical pr operties of the epilayers showed a strong crystallographic orientation dependence. With an increase of the surface offset single, the hole c oncentration of CBr4-doped GaAs and AlGaAs epilayers rapidly decreased showing a hump at (311)A. The trend of the hole concentration depende nce on the offset angle was not changed with growth temperatures in th e range of 550-650 degrees C. Carbon incorporation is much higher in A lGaAs than in GaAs. (C) 1997 American Institute of Physics.