Crystallization of a-Si films with smooth surfaces by using Blue Multi-Laser Diode Annealing

Crystallization of ∼50-nm-thick amorphous Si (a-Si) with a smooth surface was achieved by using Blue Multi-Laser Diode Annealing (BLDA). The a-Si films were deposited by using RF sputtering with Ne gas or by using plasma enhanced chemical vapor deposition (PE-CVD) and were annealed by using BLDA with CW scanning. After the films had been annealed a relatively low laser power below 4 W, the root-mean-square (RMS) roughness deduced from the atomic force microscopy (AFM) results for the surfaces of the Si films was slightly increased, but smoothness was within 3 nm despite the conditions under which the films had been crystallized. BLDA has a potential to realize next-generation poly-Si thin film transistors (TFTs).