SILICON ATOMIC LAYER GROWTH USING FLASH HEATING IN CVD

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-degrees-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-degrees-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-degrees-C and 320-degrees-C by using SiH4 and Si2H6, respectively, and the surface flatness of the deposited films was as good as that of the initial surface.