Tribochemistry-induced direct fabrication of nondestructive nanochannels on silicon surface

A tribochemistry-induced nanofabrication approach is proposed to produce nondestructive nanochannels directly on monocrystalline silicon surface. Without any masking or etching process, nanochannels with designed depths can be fabricated on silicon surface by sliding a SiO2 tip under low contact pressure in humid air. Fabrication depth increases with increasing applied load and number of sliding cycles. During fabrication, contact pressure does not result in the plastic deformation of silicon, and the material removal of monocrystalline silicon is dominated by the tribochemical reaction at the SiO2/silicon interface. High-resolution transmission electron microscopy on the cross section of the fabrication area indicates no lattice distortion beneath the nanochannels, which supports the tribochemistry mechanism. Experimental result reveals that even after 15 000 times of sliding fabrication, no obvious shape change in the SiO2 tip can be observed before and after fabrication. As a maskless, straightforward, and crystal plane-independent nanofabrication approach, it provides a new strategy to obtain nondestructive monocrystalline silicon nanostructures.