Author/Authors :
Lankinen، نويسنده , , A. and Knuuttila، نويسنده , , L. and Tuomi، نويسنده , , T. and Kostamo، نويسنده , , P. and Sنynنtjoki، نويسنده , , Hélder A. and Riikonen، نويسنده , , J. and Lipsanen، نويسنده , , John H. and McNally، نويسنده , , Arthur P.J. and Lu، نويسنده , , X. and Sipilن، نويسنده , , H. and Vaijنrvi، نويسنده , , Anthony S. and Lumb، نويسنده , , D.، نويسنده ,
Abstract :
Crystal defects of GaAs thin films deposited by metalorganic vapour phase epitaxy on high-quality Ge substrates are studied by synchrotron X-ray topography. The GaAs thin films were measured to have ≈ 500 dislocations cm - 2 , which is a similar number to what plain Ge substrates show. The dislocation densities measured are also smaller than, for instance, those of high-quality vapour pressure controlled Czochralski grown GaAs wafers, which typically have dislocation densities of ≈ 1500 cm - 2 . The GaAs films grown on both sides of two-sided substrates display very good crystal quality throughout the sample.
Keywords :
Crystal defects , X-ray topography , Germanium , X-ray detectors , Gallium arsenide , Heterostructures
