We have succeeded in obtaining nondoped, thin poly-Si film (thickness ∼500Å)
with excellent crystallinity and large grain size (Maximum grain size ∼4.5 μ
m) by an excimer laser annealing Method, which offers the features of
low-temperature processing and a short processing time. The grain size
distribution shrinks in the region around 1.5 μ m and this poly-Si film
exhibits a strong (111) crystallographic orientation. Poly-Si thin film
transistors using these films show quite a high field effect mobility of
440cm2/V · s below 600°C process.