Effect of sliding velocity on tribochemical removal of gallium arsenide surface

During machining and polishing of GaAs, surface material removal has become an issue of much concern. By using an atomic force microscope and a spherical SiO2 tip, the nanoscratch tests were conducted on GaAs(100) surface under various sliding velocities. The depth of the scratches increases with the decrease in the sliding velocity. High-resolution transmission electron microscope (HRTEM) detection shows that no damage, such as lattice distortion, dislocation and crystal slipping, can be found from the cross-section of the scratches created at various sliding velocities. Further analysis suggests that the material removal on GaAs surface may be attributed to the dynamical formation and break of interfacial chemical bonds. Compared to low-speed sliding, high-speed sliding will induce a much larger rate of material removal of GaAs surface. Therefore, if the SiO2 particles are used in the polishing of GaAs surface, high polishing speed can bring high rate of tribochemical removal without damage to the surface matrix of GaAs.