CVD金刚石膜的压阻及其温度特性

The Piezoresistances and its Temperature Characteristic of CVD Diamond Films

在Fuchs Sondheimer(F S)薄膜理论的基础上,通过求解弛豫近似下的Boltzmann方程,求出了P 型金刚石膜的电导率。在价带分裂模型下得到了压阻的计算公式,计算了微应力作用下金刚石膜的压阻,压阻和应力的变化(Δε)有比较好的线性关系,张应力情况下压阻大于零,压应力情况下压阻小于零。从理论上给出了压阻和温度的关系,计算了压阻随温度的变化,压阻随着温度的上升而单调减小。

Based on the Fuchs-Sondheimer thin film theory (F-S film theory),we have presented the conductivity of p-type diamond films by solving the Boltzmann transport equation in the relaxation time approximation.A calculating expression of the piezoresistances (PR) is obtained by using the valence band split-off model. The PR of diamond films is calculated under weak strain. It shows a good linear relation between the PR and the strain. The PR is plus under tensile strain but minus under compressive strain.Hence the theoretical description of the relation between PR and temperature is presented. The PR was calculated with the changes of temperature. It shows that the PR decreases with the increasing of temperature.