Nanotribological behaviors of friction-induced hillocks on monocrystalline silicon

With an atomic force microscope, friction and wear behaviors of the friction induced hillocks on monocrystalline silicon were investigated. With the increase of normal load from one to twelve microNewtown, the friction force on silicon substrate showed a sharp increase at eight microNewtown, while the friction force on the hillocks kept a stably linear increase. Since no scratch damage was detected on the hillock below a contact pressure of ten point three gigaPascal, the friction induced hillocks on silicon can withstand the typical contact and sliding in dynamic devices. It was also noted that the friction induced hillock presented anisotropic friction and wear behaviors during scratching. The sliding parallel to the scanning direction for producing the hillock can reduce the friction in dynamic devices. This study can shed new light on potential application of the friction induced nanostructures.