3D Modelling of Temperature Dependent Power Distribution During Microwave Annealing of Doped c-Si

Abstract

Recrystallized silicon solar cells using microwave annealing will require adequate modelling of microwave power distribution to predict the uniformity of re-crystallization of silicon, specially at high temperatures. Since, recrystallization will have to be carried out of doped silicon, doping dependence of such processes at high temperatures is also very important. This work reports modelling results for temperature and doping dependence of microwave spatial power distribution in c-Si wafer during microwave annealing. Temperature dependence was introduced through bandgap, effective mass and lattice scattering terms in Drude model of free-carrier concentration. Dependence of doping was introduced through free-carrier dependent complex dielectric function. Absorption of power was then calculated from the complex part of the dielectric constant. The 3D Modelling was carried out using Exact Finite Difference Method. All results presented in this paper are for Industrial, Scientific and Medical (ISM) frequency of 2.45 GHz.