Study of PbTe(Ga) evaporation using a nanosecond pulsed laser

Vapor composition and temperature, and time-of-flight (TOF) distributions of the vaporized particles have been studied for vacuum evaporation of PbTe(Ga) by pulses of a Nd3+:YAG laser. A quadrupole mass spectrometer and the optical multichannel analyser (emission spectroscopy) have been used for this purpose. It has been observed that the composition of the evaporated substance, ion-neutral particle ratio and TOF distributions depended strongly on the laser pulse energy density w in the region of w = 0.47–4.8 J/cm2. Estimations of the kinetic energies of the ions have been carried out. The laser plasma temperature changed from 8000 to 4500 K at w = 4.8 J/cm2 for a space of 25 mm from the target surface along the normal.