DEPTH PROFILING A III-V MULTILAYERED STRUCTURE WITH AN EXCIMER-LASER - AN APPLICATION OF DIGITAL ETCHING

A multilayered structure of GaAs and AlGaAs was depth profiled using t he technique of digital etching. A single excimer laser (KrF) was used to control the etch rate and to identify each layer by monitoring the Ga ions generated during the desorption process. The Ga ions were the only ions observed and were only generated when the photon flux was i n the GaAs layer. The etch rate, 0.9 monolayers (2.5 angstrom) per pul se, was constant with depth. The overall layer recognition resolution was 45 monolayers.