AN ANGLE-RESOLVED TOF STUDY ON THE UV LASER-INDUCED ETCHING OF INP(100) SURFACE WITH CHLORINE

Angular and velocity distributions of desorbing products from UV laser-induced etching of InP(100) surface with a supersonic chlorine molecular beam have been measured with a rotatable quadrupole mass spectrometer. Pulsed laser irradiation at 355 nm produced InCl angular distributions can be fit by I(theta) = a cos-theta+ (1 - a) cos(n)theta. This implies that there are two different desorption channels, one thermal and the other nonthermal. The mean kinetic energy of the InCl is strongly peaked around the surface normal and decreases with increasing detection angle. The laser fluence dependence of the angular distributions of desorbing products is discussed.