Role of Hydrogen in Polycrystalline Si by Excimer Laser Annealing
The role of hydrogen in the Si film during excimer laser annealing (ELA) has been successfully studied by using a novel sample structure, which is stacked by a-Si film and SiN film. Hydrogen contents in the Si films during ELA are changed by preparing samples with hydrogen content of 2.3-8.2 at.% in the SiN films with a use of catalytic (Cat)-CVD method. For the low concentration of hydrogens in the Si film, the grain size increases by decreasing hydrogen concentration in the Si film, and the internal stress of the film decreases as increasing the shot number. For the high concentration of hydrogens in the Si film, hydrogen burst was observed at 500 mJ/cm 2 and the dependence of the internal stress on the shot number becomes weak even at 318 mJ/cm 2 . These phenomena can be understood basically using the secondary grain growth mechanism, which we have proposed.
Characteristics of Recrystallized poly-Si Film Prepared by ELA of a-Si Deposited on SiO2 / SiN / Glass Using PE-CVD Method
Mem Fac Eng Yamaguchi Univ
Grain‐Growth Mechanisms in Polysilicon
The electrical characteristics of polycrystalline silicon layers are closely related to their grain structure. This paper describes a comprehensive study of the grain growth of polysilicon under a wide range of doping and processing conditions. A grain‐growth model has been developed and implemented in the SUPREM process simulator, and the simulated results are compared to those obtained by transmission electron microscopy for As‐, P‐ and B‐doped polysilicon. These results indicate that n‐type dopants increase the growth rate whereas the p‐type dopant has a negligible effect.