The role of ions and UV radiation in gallium arsenide etching process

The mechanism of gallium arsenide etching in a chlorine-argon plasma was st udied. The absorption-desorption model was proposed which explains an incre ase in etching rate upon chlorine dilution with argon by enhancement of the efficiency of active site cleaning with plasma UV radiation and ion fluxes . The processes of desorption of etching products from the surface by ions and UV photons were shown to be energetically favored. The amount of active sites cleaned per ion or photon was calculated. The addition of argon was assumed to change the proportion of active sites. Procedures for calculatin g fluxes of reactive species onto the surface and the probability of ultrav iolet light- and ion-induced desorption were detailed.