Analysis of Si-F Bonds on Si(111) Surface by Electrochemical Method

摘要

Electrochemical current at Si(111) has been investigated in dilute HF solution as a function of surface pretreatment which controls the amount of Si-F bonds on the surface. When the partly F-covered surface is immersed in dilute HF solution, anodic current transient flows as the surface Si atoms bonded to F atoms dissolve into the solution and the surface is hydrogen terminated. The anodic current becomes very small if the F-covered surface is treated with oxygen-free water, which is effective for removing Si-F from the surface and for making a completely hydrogen-terminated Si(111) surface. All results suggest that the anodic current can be a good measure for the evaluation of a small amount of Si-F bonds on Si surfaces.