Crystal Growth Mode of Poly-Si Prepared by ELA : Relationship between the Grian Morphology and Hydrogens

We investigate the characteristic of the poly-Si film prepared by the excimer laser annealing (ELA) of a-Si deposited using plasma enhanced chemical vapor deposition (PECVD) method on SiO2 / SiN / glass substrate (SiN substrate). Compared with the poly-Si film prepared by ELA of a-Si deposited by low-pressure chemical vapor deposition (LPCVD) on the quartz substrate, the Raman intensity of the poly-Si film on the SiN substrate is larger than that on the quartz substrate. The stress of the poly-Si film on the SiN substrate is smaller than that on the quartz substrate. The average grin size of the poly-Si film on the SiN substrate is approximately 70nm, and the disk-shaped grain, which is observed for the poly-Si film on the quartz substrate, is not observed. The avarage roughness (Ra) of poly-Si surface on the SiN substrate is larger than that on the quartz substrate. These phenomena are due to the difference of the crystal growth mechanims of the poly-Si film between on the SiN substrate and on the quartz substrate. We discuss these mechanisms from a viewpoint of the hydrogens included in the film and the origin of them.

excimer laser annealing

Sin substrate

poly-Si

hydogens

burst

crystal growth mechanism