Micro-machining of metal surfaces by scanning probe microscope

首先，我们建立了一个扫描探针显微镜（SPM）系统的微加工研究。SPM系统由SPM单元、气氛控制装置和测量/控制系统组成。该装置具有测量侧向力图像和法向力图像的功能。其次，我们研究了在空气中利用金刚石针尖安装在悬臂梁末端的SPM对纯金属表面进行微细加工。通过气相沉积或机械抛光块状金属制备纯金属样品，例如Ni、Cu和Au。用0.5-3 μ m x方向宽度和0.5-20 μ N加载力的x-y扫描刮擦样品表面，用小于0.1 μ N的加载力通过相同的SPM观察刮擦区域的形貌。在Ni上获得5-50 nm深度的平的正方形凹陷，尽管在Cu和Au上观察到由去除的材料的粘附引起的脊。此外，在Ni的情况下，划痕深度随着载荷力和划痕重复次数的增加而增加。划痕深度与x方向扫描线数有很大关系，而与x方向扫描速率和x-y方向扫描宽度关系不大。结果表明，纳米级厚度的材料去除可以控制。微细加工的机理取决于金属的塑性、附着性和氧化表面等因素。本文提出的方法对各种材料的微细加工具有重要的应用价值。

First, we constructed a scanning probe microscope (SPM) system for micromachining studies. The SPM system consists of a SPM unit, an atmosphere control apparatus and a measuring/controlling system. The SPM unit has a mechanism which can measure the lateral force images as well as the normal force images.Secondly, we studied micro-machining of pure metal surfaces in air by the SPM that has a very sharp diamond tip mounted on the end of a cantilever beam. Samples of pure metals, such as Ni, Cu and Au, were prepared by vapor deposition or mechanical polishing of bulk metals. Sample surfaces were scratched with x-y-scanning of 0.5-3 mu m x-direction width and 0.5-20 mu N loading force, and topographies of the scratched area were observed by the same SPM with a loading force of less than 0.1 muN.Flat square hollows of 5-50 nm depth were obtained on Ni, although the ridge caused by the adhesion of removed materials were observed on Cu and Au. In the case of Ni, moreover, the scratched depth is increased with increasing loading force and repetition numbers of scratching. The scratched depth is also strongly dependent on numbers of x direction scan line, but scarcely on x direction scan rate and x-y direction scan width. Results obtained indicate that the nano-scale thickness material removal can be controlled. The mechanism of micro-machining should be determined by several factors such as plasticity, adhesive property and oxide surface of metals. The method presented here will be powerful for micro-machining of various materials.