Nucleation-Initiated Solidification of Thin Si Films

作     者：S. Hazair P. C. van der Wilt Y. Deng U. J. Chung A. B. Limanov James S. Im 

作者机构：Program of Materials Science Department of Applied Physics and Applied Mathematics Columbia University New York USA 

出 版 物：《MRS Online Proceedings Library》 

年 卷 期：2011年第979卷第1期

页      面：1-6页

主　　题：Si nucleation & growth thin film 

摘      要：Thin Si films on SiO2 that are completely melted by pulsed laser irradiation cool rapidly and eventually solidify via nucleation and growth of solids. It has been observed that a variety of solidified microstructures can be obtained, depending primarily (but not exclusively) on the degree of supercooling achieved prior to the onset of nucleation. This paper focuses on investigating one particular and unusual polycrystalline microstructure that consists of “flowerlike grains, the interiors of which can be described as being made up of two distinct regions: (1) an extremely defective core region consisting of fine-grained material, and (2) an outer region consisting of relatively defect-free crystal “petals that radiate outwards. After considering the microstructural details and experimental behavior of the microstructure, we have formulated a growth-based physical model to account for the formation of the microstructure. The model is found to be also capable of accounting for other complex and unusual microstructures obtained via nucleation and growth in the complete melting regime.