Charge storage characteristics of metal-induced nanocrystalline in erbium-doped amorphous silicon films

Amorphous silicon film (α-Si) doped with uniform erbium (Er) impurities is deposited by laser ablation technology. High density silicon nanocrystals (nc-Si) can be formed after the rapid thermal annealing (RTA) process. The crystalline process can be explained as the 'metal-induced nanocrystalline mechanism', i.e., doped erbium atoms introduce additional strain in the amorphous silicon matrix and behave as nucleation centers during the thermal annealing process. Through this method, Si nanocrystals with high density and self-limited size distribution can be obtained. The experimental results demonstrate that the Er-induced nanocrystalline silicon film has good charge storage characteristics. It is shown that the optimal condition for the Er-induced nanocrystalline layer in α-Si is with 1 wt.% Er concentration and 1100 deg. C RTA process for 30 s