DIGITAL ETCHING OF III-V MULTILAYERED STRUCTURES COMBINED WITH LASER IONIZATION MASS-SPECTROSCOPY - PHOTON-ASSISTED DEPTH PROFILING

A photochemical method for depth profiling multilayered structures of GaAs and AlGaAs is presented. The process combines surface chlorination reactions using molecular chlorine, desorption of surface chlorides, and single step laser ionization time-of-flight mass spectroscopy. Pulsed excimer lasers are used for the desorption and ionization steps. The etch rates approached a monolayer per pulse for both substrates. Prospects for improving the resolution of the process in the lateral and vertical dimensions are discussed.