Analysis of Si-F bonds on Si(111) surface by electrochemical method

Electrochemical current at Si(111) has been investigated in dilute HF solut ion 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 dil ute HF solution, anodic current transient flows as the surface Si atoms bon ded to F atoms dissolve into the solution and the surface is hydrogen termi nated. The anodic current becomes very small if the F-covered surface is tr eated with oxygen-free water, which is effective for removing Si-F from the surface and for making a completely hydrogen-terminated Si(111) surface. A ll results suggest that the anodic current can be a good measure for the ev aluation of a small amount of Si-F bonds on Si surfaces. (C) 2000 The Elect rochemical Society. S1099-0062(00)06-055-7. All rights reserved.