結晶格子をスケールとするサブナノメートル測長・加工機の開発研究

当晶体无应力时，大约0.2 nm的晶格间距在很长的范围内是稳定和均匀的。利用扫描隧道显微镜(STM)可以在空气中获得晶体表面的原子图像。以晶体表面为参考标尺，以扫描隧道显微镜为探测器的数字点阵标尺，提供了一种以亚纳米分辨率测量长度或位移的方法。主要研究结果如下：(1)利用超低线膨胀玻璃制作了超低热漂移扫描隧道显微镜。研制了温度波动小于0.05K的热稳定电池。利用这两种仪器在室温下获得了小于0.2 nm/h的最小热漂移，并获得了长达5微米的石墨原子图像。这一结果证明了利用规则晶格进行超5微米长度测量的可行性。(2)提出了参考规则晶面原子阵列对扫描隧道显微镜针尖位置进行跟踪和运动控制。在石墨晶体上沿原子阵列的最大跟踪长度约为100 nm。这种控制方法可以推广到利用规则晶格进行亚纳米分辨率的实时长度测量。

A lattice spacing of approximately 0.2 nm is stable and uniform over long range when the crystal are stress free. Using a scanning tunneling microscope (STM), it is possible to obtain an atomic image on crystalline surface in air. A digital lattice scale, obtained by combining a crystalline surface as reference scale and a STM as a detector, offer one method to measure length or displacement with subnanometer resolution. The following results were obtained.(1) An ultralow thermally drifted STM was constructed from ultralow linear expansion glass. Thermo-stabilized cell with temperature fluctuation of less than 0.05K was also developed. Using the both instruments minimum thermal drift of less than 0.2 nm/h at room temperature was achieved and a 5-micrometer-long atomic image of graphite was obtained. This result show feasibility of length measurement over 5-micrometer using regular crystalline lattice.(2) Tracking and movement control of the tip position of a STM by referring to atomic array on regular crystalline surface was developed. The maximum tracking length along atomic array on crystalline of graphite was around 100 nm. This control method can be extended to real-time length measurement with subnanometer resolution using regular crystalline lattice.