Removal of SiO ₂ from Si (100) by remote H ₂/SiH ₄ plasma prior to epitaxial growth

This study demonstrates the cleaning of Si(100) surfaces with a remote H ₂/SiH ₄ 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 SiO ₂. 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 SiH ₄ and the etching of the deposited Si by atomic H. During the neutral deposition mode the SiO ₂ was removed without deposition of Si on the SiO ₂ surface. Once the SiO ₂ layer is removed, the underlying Si surface is exposed to the H ₂/SiH ₄ 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).