AbstractIn this work, was investigated both numerically and experimentally, the excimer laser processing of a-Si films deposited on SiO2-coated glass substrates, using the very large area (∼ 20 cm2) and long pulse duration (200 ns) excimer source from SOPRA Company. Experiments were carried out in air or in neutral atmosphere, using both the single- and multi-shot mode. From the microstructural analysis of the laser irradiated area the formation of a large-grained material through the so-called SLG regime was evidenced. In addition, the application of a multi-shot process was demonstrated to be very efficient to prepare uniform polysilicon layers with enlarged grain sizes (up to 1.5 µm after 20 shots). Finally, poly-Si TFTs prepared in the optimized conditions (multi-shot, neutral ambience) exibited field effect mobilities up to 235 cm2/V.s (for N-type) and 84 cm2/V.s (for P-type), with fairly uniform device characteristics over large area and excellent stability under electrical stress.
Advances and challenges in KSTAR plasma control toward long-pulse, high-performance experiments
