The microstructural change of the surface and the subsurface regions of a Si single crystal (Si(100)) after scratching tests under very small loading forces was investigated. First, the scratching tests were carried out using an atomic force microscope (AFM). Then, the profiles of those wear traces which were generated by the scratching tests were observed using a transmission electron microscope (TEM). TEM observations revealed that dislocations were activated in the sub-surface within less than 100 nm depth from the surface of the wear traces when the loading force was higher than 5 mN. When the loading force was higher than 20 mN, patches of amorphous Si was observed occasionally at the surface of the wear traces. High-resolution TEM (HRTEM) observations revealed that a dislocation introduced by the scratching test was a total dislocation with Burgers vector of 1=2h110i.

In this study, the microstructural change of the surface of Si single crystal (Si(100)) after the scratching tests under very small loading forces was investigated. At first, line-scratching tests and scanning-scratching tests were carried out using an atomic force/friction force microscope (AFM/FFM). Next, cross-sectional TEM observations of the wear marks which were generated by the scratching tests were carried out. As a result of the TEM observations after the line-scratching tests, it was found that dislocations were observed in the area of less than 100nm thickness from the surface of the wear marks which were formed under the loading forces of more than 5μN. In the case of the loading forces of more than 20μN, an amorphous region was also observed just under the wear marks. As a result of the TEM observations after the scanning-scratching tests, it was found that the introduction of dislocations took place and no amorphous region appeared. It was also found that the several atomic layers at the top surface of the wear marks shifted in parallel to (100).