Publication: Atomic transport in compound semiconductors
Abstract
Knowledge of atomic transport in semiconductor materials is essential not only for developing process technology but also for estimating the useful life of the devices based on compound semiconductor films. Self diffusion of constituent atoms takes place due to the presence of defects. The results of self diffusion studies in InSb crystals reported in literature are discussed. The possible mechanism of atomic migration in InSb crystals is explained as due to the formation of antisite defects. Atomic transport in thin films of CuInSe2 are reported for the first time. Flash evaporated films were used in the present study. Self diffusion of In in CuInSe2 films has an activation energy 0.45+/-0.02 eV and that for Se 0.26+/-0.02 eV. These activation energies are attributed to grain boundary diffusion When CuInSe2 films were subjected to electrical stress of 6 x 10(4) A/cm(2) migration of In atoms towards the cathode is observed The films were annealed at different temperatures in the range 500 - 600 K at the same time passing current of density 6 x 10(4) A/cm(2). The drift velocity V-d and the electromigration effective charge number Z were estimated by the quasi steady state method. The electromigration effective charge number is found to decrease with increase of temperature indications grain boundary migration of indium atoms towards the cathode. Both self diffusion and electromigration results on CuInSe2 films are being reported for the first time in this paper.