Low-Temperature Si Surface Cleaning by Hydrogen Beam with Electron-Cyclotron-Resonance Plasma Excitation

Abstract
Si surface cleaning is successfully carried out at as low as 400°C using hydrogen ECR plasma. SIMS analysis reveals no detectable accumulation of either carbon or oxygen at the grown-layer/Si interface. Hydrogen plasma cleaning is found equally effective for unbiased and positively biased Si substrates. On the other hand, helium plasma is not as effective as hydrogen plasma for cleaning. These results imply that the major mechanism involved in the plasma cleaning is chemical reaction between silicon oxide and chemically active hydrogen radicals, rather than physical bombardment by hydrogen ions.