Existence of threshold density in silicon surface cleaning using hydrogen electron cyclotron resonance plasma

Abstract

Silicon surfaces were cleaned using hydrogen electron cyclotron resonance (ECR) plasma, and were analyzed by x-ray photoelectron spectroscopy after exposure to air. For cleaning a silicon surface, a threshold density exists to remove a surface oxide layer using hydrogen ECR plasma. Cleaning was promoted when the electron density was higher than the threshold density. The threshold density seems to depend on the base pressure. In the experiment, the threshold density was about 1010 cm−3 at the base pressure of 8×10−7 Torr.