Temperature dependence of carrier transport in polycrystalline silicon

Abstract

The carrier transport in polycrystalline silicon was studied over a wide temperature range, from 20K to 300K, and for a number of dopant concentrations ranging from 1.3×10 18 /cm 3 to 2.6×10 18 /cm 3 . A grain boundary carrier trapping model was used to explain the experimental results in this work. Carrier transport by thermionic emision over the grain boundary potential barrier and thermionic field emission through the potential barrier were both included. Special attention was paid to carrier freezeout at low temperatures. The potential barrier height, V B , was shown to be an increasing function of temperature and a decreasing function of dopant concentration. The relative importance of thermionic emission and thermionic field emission was discussed.