Synchrotron X-ray topography study of defects in indium antimonide P-I-N structures grown by metal organic vapour phase epitaxy

Abstract

InSb p-i-n structures were grown on an undoped InSb wafer in a horizontal metal organic vapour phase epitaxy reactor. 200 to 300 nm thick layers were fabricated using silane and zinc as dopant sources for the n-type and p-type layers, respectively. The defects of these samples were studied using synchrotron X-ray topography in large area transmission and transmission section geometries. Pendellösung fringes typical of a nearly perfect crystal were seen in the transmission section topographs. Large area transmission topographs showed dynamical diffraction images of voids and precipitates. Also straight and circular arc dislocations were observed. Most of the images seen in the topographs arise from the defects in the epilayers. Assuming that all precipitates and voids of the layer have been imaged the average precipitate and void density was calculated to be 4000 cm⁻² or 2 × 10⁸ cm⁻³ in the best sample.