Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5361652 | Applied Surface Science | 2009 | 6 Pages |
Abstract
In this paper, we investigated the mechanism of crystallization induced by femtosecond laser irradiation for an amorphous Si (a-Si) thin layer on a crystalline Si (c-Si) substrate. The fundamental, SHG, THG wavelength of a Ti:Sapphire laser was used for the crystallization process. To investigate the processed areas we performed Laser Scanning Microscopy (LSM), Transmission Electron Microscopy (TEM) and Imaging Pump-Probe measurements. Except for 267Â nm femtosecond laser irradiation, the crystallization occurred well. The threshold fluences for the crystallization using 800Â nm and 400Â nm femtosecond laser irradiations were 100Â mJ/cm2 and 30Â mJ/cm2, respectively. TEM observation revealed that the crystallization occurred by epitaxial growth from the boundary surface between the a-Si layer and c-Si substrate. The melting depths estimated by Imaging Pump-Probe measurements became shallower when the shorter wavelength was used.
Keywords
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Physical Sciences and Engineering
Chemistry
Physical and Theoretical Chemistry
Authors
Yusaku Izawa, Shigeki Tokita, Masayuki Fujita, Takayoshi Norimatsu, Yasukazu Izawa,