Crystallization of amorphous silicon films by Cu-field aided rapid thermal annealing

Abstract

In this study, a technique, field aided rapid thermal annealing (FARTA) was proposed to crystallize the amorphous silicon films for a substantially short process time at low temperature. A spike shape pulsed rapid thermal annealing has been added to the field aided lateral crystallization (FALC) of amorphous silicon films deposited by plasma enhanced chemical deposition on glass. By adopting the FARTA process, directional crystallization of a-Si could be successfully achieved at 450 °C within a few hundreds of seconds. Other advanced crystallization methods such as FALC and metal induced lateral crystallization (MILC) normally require several hours for the same degree of crystallization even at 500 °C. Crystallization velocity using the FARTA process was measured to be 186.3 μm/h when the a-Si experienced 10 cycles of 60 s 450 °C thermal bias followed by 1 s 750 °C spike anneal. This value was six times faster than that by the MILC process at the same heating condition. From this study we found that both an electric field and the spike anneal are necessary for the crystallization of a-Si with a low thermal budget.