TCAD Simulation of the Influence of Grain Boundaries on the Temperature Dependence of Conductivity in Polycrystalline Silicon Films

On the basis of available concepts of defects in silicon and their impact on the concentration of free charge carriers in the material, we have developed a TCAD Sentaurus project for studying the temperature dependence of conductivity in poly-Si films. In TCAD Sentaurus environment, we have performed calculations revealing the impact of the concentration of defects and their distribution over energy on the temperature dependence of the relative change of resistivity in poly-Si films. With the example of experimentally obtained data on the relative variation of resistivity versus temperature for poly-Si mesa-insulated submicron-grid resistive strain sensors, we have shown that taking into account the charge carriers being released from traps upon heating offers an adequate description to the observed dependences, where not only the value of the temperature coefficient of resistance but, also, the sign of this coefficient undergoes changes with temperature.