Mechanical and electrical properties of the phosphor-doped nano-silicon film under an external electric field

The mechanical and electrical properties of the phosphor-doped nano-silicon film (nc-Si: H) prepared by the plasma-enhanced chemical vapor deposition (PECVD) method under electric field have been studied by Tribolab system, which is equipped with nano-electrical contact resistance (ECR) tool. During indentation, different voltages and loads were applied. The topography of the sample surface was studied by atomic force microscopy (AFM). The experimental results show that the roughness of the film is 5.69 nm; the electric current was measured through the sample/indenter tip with different loads at a fixed voltage, and it increased nonlinearly during the indentation. The maximum current value depth was shallower than the maximum depth of each indent due to the plasticity of the film. When the loading speed is increased to 250 mu N/s, the microcrack occurred on the film; the hardness (H) and elastic modulus (E) changed with the voltage applied both in open circuit and in short circuit case, which resulted in different values of H/E rate from 0.082 to 0.096. Copyright (C) 2009 John Wiley & Sons, Ltd.