InP crystals-ion implantation and laser annealing: RHEED, XPS and computer simulation studies

Abstract

Reflection high-energy electron diffraction (RHEED) and X-ray photoelectron spectroscopy (XPS) were used to demonstrate the effects of Zn +-ion implantation and subsequent low-power pulsed laser annealing (LPPLA) on the crystallinity and the P/In ratio near the surface of InP. The influence of ion-beam effects during depth profiling by a 1 to 5 keV Ar beam on the composition of surface layers is discussed in terms of XPS data compared to computer simulation results using a dynamic model based on TRIM. Relative enrichment in P of the topmost surface layer of virgin samples along with the P deficiency below the surface is confirmed by both XPS and computer simulation data, the effect being more pronounced for higher energies of the depth-profiling Ar + beam. Severe C and O contamination is found on the ion-implanted InP surface exposed to air. The P/In ratios at and below the surface (to about 10 nm depth) differ from that for the virgin sample. Both RHEED and XPS demonstrate the efficiency of laser pulses at a power density of 6 MW/cm 2 in recovering the structure and stoichiometry of ion-implanted crystals of InP.