Correlation between Surface Morphology and Crystal Defects of Epitaxial Layer of GaAs Grown from Vapour Phase

Some observations were made to study formation mechanism of small grooves directed on [011] on a surface of GaAs epitaxial layer, which was grown on (100) surface of Cr-doped GaAs from the vapour phase. It was tried to observe some lattice defects which may cause formation of these grooves, by etching technique, X-ray topography and transmission electron microscope. However, any lattice defects which correspond to the grooves were not found by these three methods. Therefore it was concluded that the grooves were not formed owing to lattice defects which disturbed lateral growth of the crystal. It is assumed that the grooves could be formed by gaseous etching which may take place at the end of crystal growth process