Development of laser diagnostic probes for chemical vapor deposition of InP/InGaAsP epitaxial layers

Abstract

Laser spectroscopic methods have been developed for the detection of PH3, P2, AsH3, As2, InCl, and GaCl, using both tunable-dye-laser induced fluorescence and excimer laser excitation. These are the primary reactants participating in the chemical vapor deposition (CVD) of InP/InGaAsP epitaxial layers. Using a reaction tube designed to simulate a CVD growth reactor, the detection limits measured for all these species are well below those levels typically employed during layer growth. Specific applications are outlined, and several examples are given relating these techniques to conditions expected in InP/InGaAsP layer growth.