Silicon atomic layer growth using flash heating in CVD

Abstract
Si atomic layer growth on Si was investigated by heating the surface with a Xe flash lamp in an ultraclean low-pressure environment of SiH₄ or Si₂H₆ gas. In the case of SiH₄, about 0.4 atomic layer deposition per single flash light shot was observed on Si(100) at a substrate temperature of 385°C and at a SiH₄ partial pressure of 500Pa. The adsorption process of SiH₄ can be explained quantitatively by Langmuir-type adsorption model, assuming that the total adsorption site density is equal to the surface atom density. It was found that the amount of adsorbed SiH₄ molecules is determined by the balance between adsorption and desorption of SiH₄. In the case of Si₂H₆, sub-monolayer growth of Si was observed at a substrate temperature of 320°C and under Si₂H₆ partial pressure of 300Pa. From the RHEED observation, epitaxial growth of Si films on Si(100) was confirmed to be realized at low temperatures such as 385°C and 320°C by using SiH₄ and Si₂H₆, respectively, and the surface flatness of the deposited films was as good as that of the initial surface.