AVS 49th International Symposium
    Applied Surface Science Tuesday Sessions
       Session AS-TuP

Paper AS-TuP6
Non-destructive Depth Profiling Analysis of Surface Oxidation of @beta@-FeSi@sub 2@ Thin Film on Si (100) by SR-XPS

Tuesday, November 5, 2002, 5:30 pm, Room Exhibit Hall B2

Session: Topics in Applied Surface Science
Presenter: T. Saito, Japan Atomic Energy Research Institute
Authors: T. Saito, Japan Atomic Energy Research Institute
H. Yamamoto, Japan Atomic Energy Research Institute
K. Yamaguchi, Japan Atomic Energy Research Institute
M. Haraguchi, Ibaraki University, Japan
T. Nakanoya, Japan Atomic Energy Research Institute
M. Imamura, National Institute of Advanced Industrial Science and Technology, Japan
N. Matsubayashi, National Institute of Advanced Industrial Science and Technology, Japan
T. Tanaka, National Institute of Advanced Industrial Science and Technology, Japan
H. Shimada, National Institute of Advanced Industrial Science and Technology, Japan
K. Hojou, Japan Atomic Energy Research Institute
Correspondent: Click to Email
The formation process of iron silicid (@beta@-FeSi@sub 2@) films on Si single crystal surfaces has been extensively studied because of their excellent characters as semiconductors. It is well known that stable @beta@-FeSi@sub 2@ films are not oxidized even under ambient atmospheres. However, the oxidation behaviors of the topmost surface layer of @beta@-FeSi@sub 2@ are not well understood. In the present study, we investigated the surface oxidation of @beta@-FeSi@sub 2@ thin films formed on a Si (100) surface by means of synchrotron radiation X-ray photoelectron spectroscopy (SR-XPS) to obtain the information on the surface chemical state and the depth distribution of chemical components. The @beta@-FeSi@sub 2@ films (10 - 100 nm) were formed by ion beam sputter deposition method (IBSD) or solid phase epitaxy method (SPE) at a substrate temperature of 973 K. After formation of @beta@-FeSi@sub 2@ phases, the samples were exposed to oxygen or air at room temperature. SR-XPS depth-profiling analyses revealed formation of @beta@-FeSi@sub 2@ islands on the substrates. The comparison of experimental results with simulation results using inelastic mean free paths (IMFP) of photo-electrons in Si and Fe revealed that about 50 - 70 % of the substrates surface were covered by @beta@-FeSi@sub 2@ phases. In addition, the topmost surface of @beta@-FeSi@sub 2@ and exposed Si substrates are almost completely covered by uniform thin SiO@sub 2@ layers. The thicknesses of the oxide layers were estimated at about 1.0 nm. These results indicated that thin surface SiO@sub 2@ layers behaved as a protective layer for further oxidation of @beta@-FeSi@sub 2@ surfaces.