XPS study of XeCl excimer-laser-etched InP

X-ray photoelectron spectroscopy XPS.and scanning electron microscopy SEM.have been applied to investigate the surface chemistry and morphology of InP wafers photochemically etched under 308 nm illumination from a XeCl excimer laser. The etching experiments were carried out at ambient temperature and in a low-pressure 1 mbar.atmosphere of Cl2 10%.diluted in He. During the process, the samples were exposed to laser radiation with fluences of 73 mJrcm2 or 114 mJrcm2. Both fluence values are below the ablation threshold of 140 mJrcm2 for InP. The mapping of the photoelectron spectral line intensities of In 3d5r2., Cl 2p3r2., and P 2p3r2.displayed the distribution of In–Cl and In–P compounds on the surface of the wafer. The chemical composition and morphology of the etched surface were found to be dependent on laser fluence. Surfaces with a fine granular structure were observed at a lower fluence, while at higher fluences, surfaces with a linear grating-like structure were formed. More chlorine is bound to the surface prepared at a higher fluence. q1998 Elsevier Science B.V.