Effects of Ni Overlayer and Substrate Temperature on the Lateral Growth of Poly-Si by Pulsed KrFLaser Annealing

• Main Authors: Shun-Te Cheng, 程順德
• Other Authors: Wen-Tai Lin
• Format: Others
• Language: zh-TW
• Published: 2000
• Online Access: http://ndltd.ncl.edu.tw/handle/20027416484489902164

碩士 === 國立成功大學 === 材料科學及工程學系 === 88 === Effects of patterned Ni overlayer on the lateral growth of poly-Si were studied by pulsed KrF laser annealing as a function of the energy density and substrate temperature. Upon annealing the patterned Ni overlayer absorbed the laser energy to create the thermal gradient between the capped α-Si (unmelted) and uncapped α-Si (melted). Upon cooling Si grains nucleated at the liquid/solid interface and then laterally grew into the melted region along the direction of the thermal gradient. As deep supercooling occurred in the melted region homogeneous nucleation took place, resulting in termination of the lateral growth. In the present study, lateral growth of poly-Si occurred upon annealing at an energy density of 0.3~1.0J/cm2 with a substrate temperature of 200~400℃. The grain size of poly-Si in the range of 1.0~2.0μm can be readily reached. In general, the energy density required to induce lateral growth of poly-Si decreased with the substrate temperature and the grain size of poly-Si increased with the energy density and substrate temperature. In addition, smooth NiSi2 films were formed at an energy density of 0.3~0.5J/cm2, whereas islanding NiSi2 appeared at energy densities above 0.5J/cm2.