Low surface recombination velocity on silicon wafer surfaces due to iodine-ethanol treatment

We investigated the electronic passivation of a silicon surface by iodine termination. The surface recombination velocity on iodine-terminated Si(100) was less than 10 cm/s, which is better than that obtained from oxide-passivated silicon surfaces. X-ray photoelectron spectroscopy (XPS) showed that the iodine-terminated silicon surface appeared to he covered by covalent silicon iodine bonds. This surface has no surface dangling bonds to act as recombination centers. We describe a simple model fur this surface coverage phenomena of Si-X where X is a monovalently bonded iodine atom. We demonstrate the use of iodine-ethanol solution as an alternative to oxidation for controlling silicon surface chemistry.