Fast Diffusion of H and Creation of Dangling Bonds in Hydrogenated Amorphous Silicon Studied by in situ ESR

The interaction of atomic hydrogen with a-Si:H films was studied by means of in situ ESR during H plasma treatment. H diffuses into the a-Si:H film and creates additional Si dangling bonds (∼10¹³cm^-2). We observed a high diffusion coefficient (>10^-10 cm²s^-1) at the very initial stage of H treatment (<1 s). The resulting additional dangling bonds are spatially distributed (∼100nm) into the bulk film. The characteristic depth of dangling bond (db) distribution decreases with increasing H treatment temperature. The activated rate constants of db creation and annihilation reactions determine the distribution of additional dangling bonds at different treatment temperatures.