Ultra fast melting process in femtosecond laser crystallization of thin a-Si layer
Ultra fast melting process in femtosecond laser crystallization of thin a-Si layer
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DOI：
10.1016/j.apsusc.2009.04.067
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发表时间：
2009-09-30
影响因子：
6.7
通讯作者：
Izawa, Yasukazu
中科院分区：
文献类型：
--
作者：
Izawa, Yusaku;Tokita, Shigeki;Izawa, Yasukazu
在本文中，我们研究了飞秒激光照射在晶体硅（c-Si）基板上诱导非晶硅（a-Si）薄层结晶的机制。钛宝石激光器的基频、SHG、THG 波长用于结晶过程。为了研究加工区域，我们进行了激光扫描显微镜 (LSM)、透射电子显微镜 (TEM) 和成像泵浦探针测量。除267 nm飞秒激光照射外，结晶发生良好。使用800 nm和400 nm飞秒激光照射进行结晶的阈值注量分别为100 mJ/cm(2)和30 mJ/cm(2)。 TEM观察表明，结晶是通过从a-Si层和c-Si衬底之间的界面进行外延生长而发生的。当使用较短的波长时，通过成像泵浦探针测量估计的熔化深度变得更浅。 (C) 2009 Elsevier B.V. 保留所有权利。
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 267 nm femtosecond laser irradiation, the crystallization occurred well. The threshold fluences for the crystallization using 800 nm and 400 nm femtosecond laser irradiations were 100 mJ/cm(2) and 30 mJ/cm(2), 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. (C) 2009 Elsevier B.V. All rights reserved.