Effect of counter-surface chemistry on defect-free material removal of monocrystalline silicon

Abstract To bring light on material removal remains fundamental for promoting the advancement of nanotechnology. In this study, nanoscratching test on silicon surface against Al 2 O 3 microsphere was performed using an atomic force microscope, and the material removal by SiO 2 microsphere sliding was taken as a comparison. It was found that nanochannels can be produced on silicon surface by Al 2 O 3 microsphere scratching under much lower contact pressure than the yield limit for plastic deformation, which can be ascribed to water-participated tribochemical reactions. The tribochemical removal was verified by high resolution transmission electron microscope (HRTEM) detection. Further analysis indicates that the tribochemical reactions on silicon surface are strongly affected by the counter-surface chemistry. It is noted that counter-surface chemistry influences the tribochemical reactions via altering the activation energy barrier for forming bonding bridge, and has little influence on decreasing the activation energy barrier for the rupture of Si-Si backbonds in silicon substrate. Compared with SiO 2 tip, Al 2 O 3 tip has longer working life span, and the nanochannels fabricated by Al 2 O 3 tip under the same processing conditions exhibit better uniformity even in KOH solution. The results provide useful knowledge for chemical mechanical polishing and tip-based nanomanufacturing processes, and shed new light for enriching the basic theory of nanotribology.