Ultra-Microscopic Analysis of Metal-Compound Semiconductor Interfaces by the Atom-Probe Mass Analyzer

利用原子探针质量分析仪对金属化合物半导体界面进行超显微分析

基本信息

批准号：
59420038
负责人：
NISHIKAWA Osamu
金额：
$ 12.16万
依托单位：
Tokyo Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (A)
财政年份：
1984
资助国家：
日本
起止时间：
1984 至 1985
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-59420038/
关键词：
Combined atom-probe Pulsed-laser GaAs GaP Al-GaAs interface 金属-化合物半導体界面

项目摘要

The voltage-pulse atom-probe(A-P) analysis of compound semiconductors tends to give an erroneous composition, e.g. more As ions than Ga ions are detected from GaAs. The newly constructed combined A-P of straight, deflected and imaging types made it possible to clarify the cause of the erroneous compositions as the preferential field evaporation of Ga immediately after the evaporation of nearby As atoms. Then it was successfully demonstrated that the A-P can give stoichiometric compositions by adjusting the deflector and pulse voltages.The unique features of the combined A-P are high ion detectability by a chevron electron multiplier with a wide effective incoming area and by a signal height discriminating time digitizer, high-speed data process by a 32-bit computer, and monitoring of an imaging A-P with a storage oscilloscope.Another anticipated approach to analyzing compound semiconductors is to promote field evaporation by irradiating a specimen with a pulsed-laser beam, 0.8 ns wide and a peak power of 200 KW. The present study pointed out that even the A-P analysis with a pulsedlaser fails to give a right composition unless the laser power and tip voltage are not properly adjusted. Utilizing the result of the present study, Al-GaAs interfaces were analyzed by the pulsed-laser A-P, comparing the result obtained by the voltage-pulse A-P. Unexpectedly, a Ga layer was found at the interface of an AlAs layer and the substrate GaAs. At present, the formation mechanism of the Ga layer is under investigation.

化合物半导体的电压脉冲原子探针 (A-P) 分析往往会给出错误的成分，例如从 GaAs 中检测到的 As 离子多于 Ga 离子。新构建的直线型、偏转型和成像型组合A-P使得能够澄清错误成分的原因，因为Ga在附近的As原子蒸发后立即发生优先场蒸发。然后成功地证明了 A-P 可以通过调节偏转器和脉冲电压来提供化学计量成分。组合 A-P 的独特之处在于通过具有宽有效入射面积的 V 形电子倍增器和信号高度辨别时间数字化仪实现高离子检测能力，通过 32 位计算机进行高速数据处理，并使用存储示波器监控成像 A-P。分析化合物半导体的另一种预期方法是通过以下方式促进场蒸发：用宽度为 0.8 纳秒、峰值功率为 200 千瓦的脉冲激光束照射样品。本研究指出，即使使用脉冲激光进行 A-P 分析也无法给出正确的成分，除非激光功率和尖端电压没有适当调整。利用本研究的结果，通过脉冲激光A-P对Al-GaAs界面进行了分析，并比较了电压脉冲A-P获得的结果。出乎意料的是，在AlAs层和衬底GaAs的界面处发现了Ga层。目前，Ga层的形成机制正在研究中。