High-throughput intermittent-contact scanning probe microscopy

Large arrays of micro-cantilevers operating in parallel are essential for achieving high throughput in such applications as life sciences, nanofabrication and semiconductor metrology. A novel intermittent-contact mode operation is presented that is suitable for such applications. The cantilevers are electrostatically actuated. The oscillation amplitude is kept small to enable high-frequency operation and to reduce the tip-sample interaction force, and thus the tip and sample wear. Input shaping of the actuation signal is employed for high-speed reliable operation in the presence of the tip-sample adhesion forces. The deflection signal is sampled once per oscillation cycle to enable high-speed imaging. Experimental results are shown which demonstrate the efficacy of the proposed scheme. In particular, during continuous high-speed imaging, the tip diameter is maintained over a remarkable 140m of tip travel. © 2010 IOP Publishing Ltd.