Homoepitaxial growth of ZnSe on dry-etched substrates

Abstract
High quality ZnSe layers have been grown by molecular beam epitaxy on dry‐etched ZnSe substrates. Surface damage caused by cutting and polishing of the ZnSe substrate was removed by dry etching using BCl3 gas to 10 μm depth. The dry‐etched ZnSe substrates exhibited smooth surface morphology and showed excitonic emissions stronger than that from as‐polished substrates in photoluminescence (PL) measurements at 11 K. The low‐temperature PL spectra obtained from homoepitaxial ZnSe layers grown on the substrates dry etched at the optimum condition showed a strong free‐exciton emission at 2.804 eV and a dominant donor‐bound exciton emission at 2.798 eV. Since each excitonic emission shows a single peak, the homoepitaxial layers appear to be free from strain.