Experimental and theoretical research for carrier mobility of thin polycrystalline silicon films in application of VLSI

The relationship of carrier mobility of polycrystalline silicon films vs. doping concentration has been investigated theoretically and experimentally. It is shown that the carrier mobility will not only take a minimum at a intermediate doping level, as pointed out by other researchers, but also take a maximum at a high doping level. The existing models cannot predict the mobility vs doping concentration completely. Based on the carrier segregation model and carrier trapping model combined with the impurity scattering mechanism, the effects of grain size and the density of trapping states at grain boundaries on the maximum of carrier mobility have been calculated. The experimental results have been explained by the theoretical model.EI04286-2931