【作者】 范志东；

【导师】 彭英才；

【作者基本信息】 河北大学 ， 微电子学与固体电子学， 2010， 硕士

【摘要】 以Au或Al膜作为金属催化剂,基于固-液-固(SLS)生长机制,直接从n-(111)单晶Si衬底上生长了具有一定直径、长度和密度分布的Si纳米线(SiNWs)。实验研究了催化剂膜层厚度、生长温度、气体流量和生长时间等工艺条件对Si纳米线生长的影响。利用扫描电子显微镜(SEM)、X射线能量损失谱(EDS)和X-射线衍射仪(XRD)对Si纳米线的形貌、组分和生长晶向进行了分析表征。结果表明,制备高密度、大面积和分布有序Si纳米线的典型工艺条件为:Au或Al膜厚度为5-10nm,生长温度为1100℃,N2或Ar气流量为1.5 L/min和生长时间为60min。其Si纳米线的直径约为50-300nm,长度为数微米到数十微米,甚至有的可达几个毫米。采用Xe灯在室温条件下测量了Si纳米线的光致发光(PL)特性,发现在400-480nm波长范围有一个强蓝光发射带,其峰值波长约为420nm。从微观组织热力学、晶体生长动力学角度定性分析了Au-Si共晶液滴的形成、Si纳米线的生长机理。分析指出,Si纳米线生长的过程主要为:金属催化剂的沉积,Au-Si共晶液滴的形成,Si在合金中的偏聚,成核并分离析出以及Si纳米线的生长。更多还原

【Abstract】 High quality silicon nanowires (SiNWs) were grown directly from n-(111) single crystal silicon based on solid-liquid-solid(SLS) mechanism use Au or Al films as metallic catalyst. The effects of metal film thickness, annealing temperature, growth time and gas flow rate on the formation of the SiNWs were experimentally investigated. The morphology and microstructure, chemical compositions and growth crystall orientation of the SiNWs were characterized and analyzed by the scanning electron microscopy(SEM), the energy-dispersive X-ray spectroscopy(EDS) and X-ray powder diffraction(XRD). The results indicated that the optimize parameters to realize Si nanowires with high density, uniform distribution and similar direction are as follows: the thickness of Au or Al film is between 5-10 nm, the temperature is 1100℃, and the flow of N2 or Ar is 1.5L/min. The diameters and lengths of the formed SiNWs are 20-300nm and from several micrometers to sereral tens of micrometerss and some even reaching millimeter level, respectively. The room temperature photoluminescence (PL) properties of the SiNWs were observed by Xe lamp. The results shown that the SiNWs have a stronly blue luminescencent band around 400-480nm with an emission peak position at 420nm. The formed process of the SiNWs is analysized qualitatively based on microstructure thermodynamics and crystal growth kinetics.The results shown that the process of the SiNWs include that the deposit of metal catalyst, the form of Au-Si eutectic droplet alloy, there is gather in partial district of Si in Au-Si, the alloy run out the undercooled region, nucleus formation and Si were separate out form Au-Si alloy and serve as seed crystal, and the SiNWs were grown.更多还原