| X-ray photoelectron spectroscopy (XPS) has been used to investigate the chemical composition of InP wafers etched by a nitrogen laser. The etching process is carried out under vacuum (10-6 Torr), and the wafers are transferred to the X-ray photoelectron spectrometer under vacuum. During the etching process, the InP wafers are exposed to light produced by a nitrogen laser with pulse energies and number of pulses of 392mJ/cm 2 (100pulses), 204mJ/cm2 (100pulses), 117mJ/cm 2 (100pulses), 117mJ/cm2 (10pulses), 56mJ/cm 2 (100pulses), or 56mJ/cm2 (10pulses).; XPS spectra shows the wafer etched with 117mJ/cm2 (10pulses) still have an oxidized layer in the etched area. The etched area is not observed from the 56mJ/cm2-etched InP wafers. The distribution maps of photoelectron intensity in In3d and P2p indicate metallic indium is tended to be present in the etched area, and elemental phosphorus near the etched area. |
