pH-responsive silicon wafer prepared by hydrogen annealing

We found that silicon wafers prepared by hydrogen gas annealing at high temperatures exhibit good pH-response while those without hydrogen annealing do not. When the pH-responsive silicon wafer is heated in air at a high temperature, e.g. 600 degrees C, so that oxide layer forms on the surface, the pH-responsive properties disappear. It is conceived that a small amount of mobile protons are present in the pH-responsive silicon wafer. The silicon wafers have a potential use for pH-electrode materials which are applicable to pH-measurement even in HF solution. (C) 1998 Elsevier Science Ltd. All rights reserved.