Early stages of oxygen clustering in hydrogenated Cz-Si: IR absorption studies

The formation kinetics of small oxygen clusters in hydrogenated Si has been studied by means of infrared absorption measurements. Hydrogen was introdu ced into the crystals by in-diffusion from H-2 gas at 1200-1300 C. The samp les were heated at temperatures in the range of 280-37 degreesC for differe nt durations. At initial stages of he:lt-treatment, enormous generation rat es of the oxygen dimer have been observed in hydrogenated samples. This ind icates highly enhanced diffusion of the interstitial oxygen atoms. The maxi mum achievable concentration of the dimers is found to be limited by their dissociation rate even at temperatures of about 300 degrees, while in as-gr own crystals the capture processes are known to be dominant in this tempera ture region. An explanation of this phenomenon is presented. (C) 2001 Publi shed by Elsevier Science B.V.