DEVELOPMENT OF A TWO DEGREES OF FREEDOM LENGTH MEASUREMENT SYSTEM USING A CRYSTAL AS THE SCALE REFERENCE

以晶体为标尺基准的二自由度长度测量系统的研制

基本信息

批准号：
03555083
负责人：
HIGUCHI Toshiro
金额：
$ 10.43万
依托单位：
UNIVERSITY OF TOKYO
依托单位国家：
日本
项目类别：
Grant-in-Aid for Developmental Scientific Research (B)
财政年份：
1991
资助国家：
日本
起止时间：
1991 至 1993
项目状态：
已结题

项目摘要

We have investigated the possibility of using the lattice spacing of a crystal for metrology and accurate positioning. To carry out the research, we have built a scanning tunneling microscope (STM) with two tunneling-units (a dual tunneling-unit STM, DTU-STM), with an xy stage with two sample holders, The configuration enables simultaneous observation of a sample and the scale-reference crystal. As a result, it is possible to calibrate the lateral scales of the sample image by superposition of the crystalline lattice image. In order to access the accuracy of this measurement procedure, we have compared crystalline lattice images acquired simultaneously with the two tunneling-units. Matching of 99.98 +/- 0.03%. Although we have not measured the absolute accuracy of the system, the high repeatability of the experiment implies the procedure to give good results. We have succeeded in the software recognition of the atomic features, so it is safe to assume that an automated measurement machine, capable of measuring up to a few microns will be implemented in the near future.Study on the use of the STM and a crystal for sub-nanometer positioning control of the xy stage was also carried out. Lateral position modulation in the 10 pm order was used to measure the gradient of the surface with atomic resolution. By this technique, it becomes possible to recognize the local maximum and minimum of the topographic features, and thus implement active positioning of the xy stage using the lattice spacing as the reference. Positioning of the STM tip to a single atom was also confirmed for tens of minutes.

我们已经研究了使用晶体间距进行计量和准确定位的可能性。为了进行这项研究，我们已经建立了一个带有两个隧道单位（双隧道单位stm，dtu-stm，dtu-stm）的扫描隧道显微镜（STM），并带有一个带有两个样品持有人的XY阶段，配置可以同时观察一次样品和比例参考晶体。结果，可以通过晶格图像的叠加来校准样品图像的横向尺度。为了访问此测量程序的准确性，我们比较了同时获得的晶格图像与两个隧道功能。匹配为99.98 +/- 0.03％。尽管我们尚未衡量系统的绝对准确性，但实验的高可重复性意味着提供良好结果的过程。我们已经成功地识别了原子能特征，因此可以肯定地假设一台能够在不久的将来实现了一台能够测量多达几微米的自动测量机。对于XY阶段的子纳米表定位控制也进行了。使用原子分辨率测量表面梯度的横向位置调制。通过这种技术，可以识别地形特征的局部最大值和最小值，从而使用晶格间距作为参考来实现XY阶段的主动定位。还确认将STM尖端定位为单个原子数十分钟。