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在表面上,在离位附近的步骤的异常螺旋运动
J B Hannon1, V B Shenoy, K W Schwarz
1IBM Research Division, T. J. Watson Research Center, Yorktown Heights, NY 10598, USA. jbhannon@us.ibm.com
概括
我们在离位附近的表面上观察到明显的步骤运动. Si(111) 呈现出经典的螺旋增长,而Si(001) 则表现出异常行为,由脱位应变场解释.
科学领域:
- 材料科学 材料科学 材料科学
- 表面科学是一门学科.
- 固态物理 固态物理
背景情况:
- 了解晶体生长机制对于半导体制造至关重要.
- 水晶格子中的失位可以显著影响表面形态和生长动态.
- 之前的模型,比如伯顿,卡布雷拉和弗兰克理论,解释了理想表面上的步进运动.
研究的目的:
- 为了研究和比较Si{111}和Si{001}表面的步骤运动,在出现位移的情况下.
- 为了阐明Si(001) 在脱位核附近观察到的异常步骤行为.
- 为了将动态步骤流动模式与位移应变场和滑动系统相关联.
主要方法:
- 使用低能电子显微镜 (LEEM) 可视化和测量步骤动态.
- 在晶体生长和升华过程中进行实验.
- 分析因位移而产生的应变场对步骤速度的影响.
主要成果:
- 在Si{111}上观察到经典的旋转阿基米德螺旋步运动,与理论预测一致.
- 记录了显著不同的,异常的步骤运动在Si () 附近的位.
- 证明来自位移的不均应变场决定了Si的局部步骤速度.
结论:
- 由于应变效应,Si(001) 上的步骤在离位附近的行为偏离了标准模型.
- 在Si(001) 上观察到的异常运动与局部应变场和脱位的滑动系统直接相关.
- 在半导体中,LEEM提供了一种强大的工具,用于研究离位介导的半导体表面现象.
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