多孔硅形成过程中的晶态转变  

Transformation of Crystalline State during Porous SiliconFormation

作　　者：吕京美[1] 程璇[2,3] LV Jingmei CHENG Xuan(School of Material and Environment, Beijing Institute of Technology, Zhuhai 519088, Guangdong, China Department of Materials Science and Engineering, College of Materials, Xiamen University, Xiamen 361005, Fujian, China Fujian Key Laboratory of Advanced Materials, Xiamen 361005, Fujian, China)

机构地区：[1]北京理工大学珠海学院,材料与环境学院,广东珠海519088 [2]厦门大学材料学院材料科学与工程系,福建厦门361005 [3]福建省特种先进材料重点实验室,福建厦门361005

出　　处：《硅酸盐学报》2017年第1期78-82,共5页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金项目(11372263);福建省特种先进材料重点实验室开放课题资助项目

摘　　要：采用电化学阳极氧化法,对p型单晶硅施加30 mA/cm^2的恒定电流密度,在40%氢氟酸溶液中和氮气保护气氛下分别极化1、3和5 min,制备不同生长阶段的多孔硅样品,通过表面形貌观测及微观结构表征,获得从单晶硅到多孔硅形成过程所涉及的各种晶态组成的相对比例。结果表明:不同极化时间制得的单晶硅表面均形成了海绵状均匀分布的纳米孔洞结构。在多孔硅的形成过程中,单晶硅结构发生了显著的晶态转变和晶粒尺寸变化,导致大单晶、纳米晶和无定形态并存,晶粒直径从初期的1.41 nm减小到并保持在0.65 nm,而晶态的转变和晶粒尺寸的变化被认为与晶格畸变程度有关。The porous silicon samples were fabricated on the p–type single crystal silicon wafers in 40% hydrofluoric acid solution under a nitrogen atmosphere by applying a constant current density of 30 mA/cm2 for 1, 3 and 5 min, respectively. The surface morphologies and microstructures of the freshly prepared porous silicon layers were investigated. The relative amounts of large single crystal, nanocrystalline and amorphous silicon related to the extent of crystallinity transformation and the change of crystallite diameter involved during porous silicon formation were evaluated via multi–peak fitting Raman spectra. The results reveal that the sponge–like nanoporous structures are formed on the silicon surfaces at different polarization time. The apparent changes in crystal structure and crystallite diameter occur during the porous silicon formation, leading to the coexistence of large single crystal, nanocrystalline and amorphous silicon. The crystallite diameter reduces to 0.65 nm from 1.41 nm for the initial growth. The degree of lattice distortion could be contributed to the crystallinity transformation and crystallite diameter variation.

关 键 词：多孔硅 单晶硅 RAMAN光谱 无定形 晶格畸变 

分 类 号：O611.2[理学—无机化学]