Published online by Cambridge University Press: 17 March 2011
In this work we will discuss the feasibility of sputtered-Si as a precursor for low-temperature p-Si films. We used DC sputtering to deposit thin Si films (30-100nm) that were subsequently crystallized by excimer-laser annealing using XeCl (308nm) irradiation. The as-deposited films were sputtered with different gases including Ar, He and Ar-He mixtures. As expected, He sputtering led to less dense films that Ar. However, the plasma voltage (during deposition) was also lower in these cases. It was found that mixing of Ar and He gases within an appropriate ratio range produced sputtered films with good optical properties, at much lower plasma voltages that Ar alone. The lower voltage application could be beneficial from the point of view of reducing microarcing and allowing application of higher DC power levels (to improve deposition rate). Polysilicon TFTs fabricated with the optimum Ar-He ratio (>5% Ar in He) demonstrate similar performance between pure-Ar and Ar-He sputtered p-Si TFTs.