Removal of SiO2 From Si (100) by Remote H2/SiH4 Plasma Prior to Epitaxial Growth

Abstract

ABSTRACTThis study demonstrates the cleaning of Si(100) surfaces with a remote H2/SiH4 plasma. The surfaces were prepared with a chemical oxide the remains after an RCA clean. The plasma cleaning process was designed to remove contaminants such as C, F, and SiO2. The key to successful removal of the oxide is to have the plasma chemistry in a neutral deposition regime. The neutral deposition process regime is a balance between the deposition of Si by SiH4 and the etching of the deposited Si by atomic H. During the neutral deposition mode the SiO2 was removed without deposition of Si on the SiO2 surface. Once the SiO2 layer is removed, theunderlying Si surface is exposed to the H2/SiH4 plasma and a thin epitaxial film may be deposited. The final Si surface configuration after plasma cleaning is a 2×1 hydrogen terminated surface. The characterization of the interface and epitaxial film were investigated using Auger electron spectroscopy (AES) and transmission electron microscopy (TEM).