Investigation of Lateral Force in Tip-Based Nanofabrication

Tip based nanofabrication has a wide application in micro/nano devices. Scratching depth is a key indicator of the machining quality. Tip tilt occurs during scratching process due to the low rigidity. Current depth models usually ignore the tip tilt. To study the effect of tip tilt on scratching depth, a series of scratching experiment is conducted to collect deformation signals of the cantilever. The tip tilt signal is used to rectify the actual scratching length. The rigidity of cantilever is obtained based on simulation and calibration experiments. Lateral force and normal force are calculated using the calibrated rigidity. Based on the measured force and rectified scratching length, an empirical model of lateral force is established in the edge forward and face forward direction. The apparent friction coefficient is also fitted in these two directions and a simplified analytical model is proposed to analyze the variation of apparent friction coefficient.