AVS 52nd International Symposium
    Electronic Materials and Processing Tuesday Sessions
       Session EM1-TuM

Paper EM1-TuM5
The Role of Etching in Film Growth during Wet Chemical Oxidation of H:Si(100)

Tuesday, November 1, 2005, 9:40 am, Room 310

Session: Defects, Interfaces, and Surface Passivation in Electronic Materials
Presenter: K.T. Queeney, Smith College
Authors: K.T. Queeney, Smith College
J.W. Clemens, Smith College
S.K. Green, Smith College
C.A. Shea, Smith College
Correspondent: Click to Email
Exposure of hydrogen-terminated Si(100) to aqueous solutions is an integral part of most wafer cleaning processes in microelectronics manufacturing. The quality of the thin oxide films formed (either intentionally or unintentionally) during this processing can have a profound effect on ultimate device performance. We have used transmission infrared spectroscopy to study this wet chemical oxidation of H:Si(100), allowing us to monitor both the evolution of SiH@sub x@ species and the growth of Si-O modes from the oxide film. While dissolved O@sub 2(aq)@ is the primary oxidizing species in H@sub 2@O, etching of the Si(100) surface by OH@super -@ species in the water plays an important role in oxidation. Sharpening of the Si-H bending modes in the earliest stages of oxidation suggests that this etching creates a more homogeneous surface, which is consistent with the high quality of the single layer SiO@sub x@ as judged by the evolution of Si-O optical phonons during oxidation. Studying the subsequent oxidation of surfaces first etched in deoxygenated water provides some temporal separation of the concomitant etching and oxidation processes and reveals that the relative reactivity of sites exposed by this etching is distinct from reactivity of analogous sites on extended Si surfaces, highlighting the importance of defect-driven chemistry during oxidation.