Characterization of surface potential and strain at ultrathin oxide/silicon interface by photoreflectance spectroscopy

• Published in: Japanese Journal of Applied Physics 1996, Vol.35 (2B), p.1073-1076
• Main Authors: IMAI, T, FUJIMOTO, A, OKUYAMA, M, HAMAKAWA, Y
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems; Electron states and collective excitations in thin films, multilayers, quantum wells, mesoscopic and nanoscale systems; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Exact sciences and technology; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of specific thin films; Optical properties of specific thin films, surfaces, and low-dimensional structures; Physics
• ISSN: 0021-4922; 1347-4065
• DOI: 10.1143/JJAP.35.1073

Si surface potential and strain at the Si–SiO 2 structure with a thermally grown or a native SiO 2 ultrathin film have been characterized by photoreflectance (PR) spectroscopy. The surface potentials of Si–SiO 2 structures are determined from the modulation light intensity dependence of the PR signal intensity. Although the signal intensity decreases drastically with increasing SiO 2 film thickness, it can be increased by applying dc bias voltage and increasing the surface potential of Si. The strains at the Si surface have been obtained by an analysis of the transition energy shift in the SiO 2 /Si structure with a thermally oxidized ultrathin film.