Abstract

We describe a microprobe analysis technique which has the potential for extremely sensitive quantitative measurements of surface and bulk concentration as well as depth profiles. This technique is termed profile analysis using laser-assisted spectroscopy (PALAS) and uses one pulsed laser to desorb or vaporize a controlled volume of the sample and a second pulsed laser to induce fluorescence in the desorbed species. The intensity of the laser-induced fluorescence provides a quantitative measure of the desorbed atom species concentration, while the energy density of the vaporizing laser controls the sampling depth. The requisite lateral resolution is provided by focusing the vaporizing laser. Present work is intended to demonstrate the feasibility of PALAS by making measurements of impurity and dopant concentrations in GaAs and InP which are III–V materials of interest. These measurements will be performed in such a manner as to demonstrate the utility of the technique as an in situ diagnostic for conditions encountered in metallo-organic chemical vapor deposition. Extensions of the technique to high and ultrahigh vacuum conditions encountered in molecular beam epitaxy and complementary surface diagnostic techniques are also possible.

© 1986 Optical Society of America