Experimental Studies of Surface Diffusion on Semiconductor Materials

半导体材料表面扩散的实验研究

• 批准号: 9121917
• 负责人: Edmund Seebauer
• 金额: $ 23.75万
• 依托单位: University of Illinois at Urbana-Champaign
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-09-15 至 1997-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9121917&HistoricalAwards=false
• 关键词: Experimental; Studies; Surface; Diffusion; Semiconductor

Surface diffusion on semiconductors is examined by direct imaging of adsorbate concentration profiles using surface second harmonic generation (SHG). Work in the antimony on germanium (111) system has demonstrated that the SHG method avoids many of the problems associated with other methods, permits extraction of the coverage dependence of the diffusivity without paramaterization, and allows observation of the effects of ambient gas pressure on surface diffusion. The present effort focusses on III-V adsorbates (including gallium arsenide) on silicon and germanium. Activation energies and preexponential factors for diffusion are measured as functions of surface concentration and of the density and orientation of surface steps. The approach is also being extended to gaseous adsorbates such as triethylgallium. The effects of various factors on diffusion are examined; these include photon flux, electric fields directed parallel to the surface, and ambient noble gases. Surface diffusion often has a primary role in governing the rates of surface reactions, particularly for those involved in the formation of thin films of semiconductors by chemical vapor deposition or molecular beam epitaxy. Control of the process and of the quality of the product are hampered by a lack of data on surface diffusion. This research produces an efficient and general methodology for obtaining such information.

本文用直接扩散法研究了半导体表面的扩散 使用表面的吸附物浓度分布的成像 二次谐波产生（SHG）。 在锑上工作 锗（111）系统已经证明， 避免了与其它方法相关的许多问题， 允许提取的覆盖依赖性的 无参数化扩散，并允许观察 环境气体压力对表面扩散的影响。 目前的努力集中在III-V族吸附物（包括 砷化镓）在硅和锗上。 激活 测量了扩散的能量和指前因子 作为表面浓度和密度的函数， 表面台阶的方向。 该方法还被 扩展到气态吸附物如三乙基镓。 的 各种因素对扩散的影响进行了研究;这些 包括光子通量、平行于 表面和环境惰性气体。 表面扩散通常在控制表面扩散中起主要作用。 表面反应的速率，特别是对于那些参与 用化学方法形成半导体薄膜 气相沉积或分子束外延。 控制 过程和产品的质量受到阻碍， 缺乏关于表面扩散的数据。 这项研究产生了一个 有效和通用的方法来获得这种 信息.