Laser induced surface chemical epitaxy: A novel thin film deposition technique

This report identifies a new deposition technique, laser induced surface chemical epitaxy, and describes experimental studies of the surface chemistry relevant to the feasibility of the technique. The experiments focus on the thermal and photo-induced surface chemistry of two organometallic molecules, dimethyl cadmium and dimethyl tellurium, on a variety of surfaces including GaAs, Au, Si, and SiO2. These studies followed ultra-high vacuum compatible procedures and used X-ray photoelectron spectroscopy to characterize thermal and photon-induced effects on the chemical state of the adsorbed organometallic molecule. The results show considerable diversity in the thermal surface chemistry of the system investigated. Physisorption and dissociative chemisorption to yield monomethyl and metal adspecies were observed. Irradiation of the physisorbed adspecies with 193 nm UV photons caused both photodecomposition and photodesorption. Similar irradiation of the photons caused both photodecomposition and photodesorption.