DEVELOPMENT OF MICROSCOPIC MEASUREMENT OF RESISTIVITY DISTRIBUTION IN MESOSCOPIC REGION

介观区电阻率分布微观测量技术的进展

• 批准号: 04650008
• 负责人: MERA Yutaka
• 金额: $ 1.34万
• 依托单位: THE UNIVERSITY OF TOKYO
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1992
• 资助国家: 日本
• 起止时间: 1992 至 1993
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-04650008/
• 关键词: Deep levels; DLTS; GaAs; High resolution; Non-contact; STM; Surface photovoltage; 表面準位; 空乏層; 半導体; 結晶欠陥

We have invented a novel methodology of non-contact Deep level transient spectroscopy (DLTS) in very high spatial resolution based on scanning tunneling microscopy (STM). An STM tip is used to detect the transitent of surface photo-voltage (SPV) induced at surfaces of semiconducting crystals. Theoretical considerations showed that under an appropriate condistion, the SPV-DLTS signal, defined by the ratio of the decay component of SPV to the total magnitude of the SPV,is proportional to the density of sub-surface deep centers that trap minority carriers on illumination, We have experimentally succeeded in measureing, for a plastically deformed n-GaAs, SPV-DLTS spectra matching those obtained by optical-DLTS.From comparison of a two-dimensional map of the SPV-DLTS signal, obtained at the spectral peak temperature, with the SPV signal distribution, we concluded that the image contrasts in the SPV-DLTS image represent the presence of minority carrier traps in the depletion layr beneath the surface. The spatial resolution reached the order of 10nm even in this preliminary expriment. If we solve the remaining technical problem of thermal drift of the STM tip during temperature scanning, the STM-DLTS will serve as a powerful tool not only for local assessment of micro-fabricated structures but also for studies of crystalline defects in semiconductors.

我们发明了一种基于扫描隧道显微镜（STM）的非接触式高空间分辨率深能级瞬态光谱（DLTS）新方法。利用STM尖端检测半导体晶体表面产生的瞬态光电压。理论分析表明，在适当的条件下，SPV- dlts信号（由SPV的衰减分量与SPV的总量级之比定义）与在光照下捕获少数载流子的亚表面深中心的密度成正比。我们已经实验成功地测量了塑性变形n-GaAs的SPV- dlts光谱与光学- dlts光谱相匹配。通过对比在光谱峰值温度下获得的SPV- dlts信号的二维图与SPV信号的分布，我们得出结论，SPV- dlts图像中的图像对比度表示在地表以下的耗尽层中存在少数载流子陷阱。在本次初步实验中，空间分辨率达到了10nm量级。如果我们解决了STM尖端在温度扫描过程中的热漂移问题，STM- dlts将成为一个强大的工具，不仅可以用于微加工结构的局部评估，还可以用于半导体晶体缺陷的研究。

项目成果

K.Maeda, M.Uota, Y.Mera: ""Spatially resolved deep level transient spectroscopy using a scanning tunneling microscope"" Mat.Sci.Eng.B42. 127-132 (1996)

K.Maeda、M.Uota、Y.Mera：“使用扫描隧道显微镜进行空间分辨深能级瞬态光谱”Mat.Sci.Eng.B42。

K.Maeda, M.Uota, Y.Mera,: "Spatially resolved deep level transient spectroscopy using a scanning tunneling microscope" Material Science and Engineering. B42. 127-132 (1996)

K.Maeda、M.Uota、Y.Mera：“使用扫描隧道显微镜进行空间分辨深能级瞬态光谱”材料科学与工程。