Fundamental studies on silicon and silicon germanium oxidation by ozone.

摘要

A novel Rapid Thermal Processing (RTP) system is designed and set up, which is capable of most semiconductor thermal processes with high vacuum capabilities, ozone formation and processing, and in-situ characterization such as Fourier Transform InfraRed (FTIR) spectroscopy, goniometry, and residual gas analysis. Mirror Enhanced Polarized Reflectance (MEPR) - FTIR spectroscopy is proposed and is shown to increase the IR intensity of the silicon oxide Longitudinal Optical (LO) mode by a factor of about 20; thus, it allows submonolayer probing of silicon oxide on Si.; Rapid thermal oxidation of Si in O₃ (950 ppm)/O₂ at 200–550°C shows higher oxidation rate than that in pure oxygen. Data analyses suggest a fast oxidation rate regime early on, followed by a slow one. Preliminary electrical characterization suggests that oxides formed in ozone ambient are of higher quality than those formed in pure molecular oxygen. The oxidation of SiGe alloys in ozone is also investigated. For all temperatures investigated, 125 to 530°C, Ge was found to be incorporated into the growing oxide.; During the initial oxidation of the H-terminated Si surface, ozone removes H from Si faster than O₂. CH₂I₂ contact angles with Si(100) in N₂ are shown to be more sensitive to the surface at high H coverages, while H₂O contact angles at low H coverages. During the transition from an H-terminated (hydrophobic) surface to an oxide covered (hydrophilic) one, the H₂O contact angle is found to decrease to a nearly asymptotic value via a minimum. During the initial stage of ozone oxidation, an ozone-related adsorption species is observed at 1732 cm −1. Such a result suggests that ozone oxidation proceeds initially via an intermediate adsorption species. Metallorganic chemical vapor deposition of Ta₂O₅ was also studied with in-situ characterization technique in the mentioned RTP system.