Pull-off Force and Stick-Slip Properties of Silicon Surface Under Environmental Humidity

Si(110) surface was modified by wet chemical etching to get regular circular and triangular texture. Then the pull-off force and stick-slip resistant performance of the smooth silicon surface and the modified silicon surface were investigated by a home-made micro-tribotester in the situations of micro load and various relative humidity levels. The results show that the modified surface can decrease the pull-off force caused by the capillary force, and also avoid the stick-slip phenomenon occurring on the smooth silicon surface when the relative humidity is over 700/0. A model based on the forming and breaking mechanism of liquid bridges was proposed to explain the principle of pull-off force and stick-slip phenomenon on bare and modified surface under environmental humidity. The model can be used to design patterns to control the capillary pull-off force and stick-slip phenomenon.