Adaptive tilting angles for a dual-probe AFM system to increase image accuracy

While the feature size of micro-fabricated structures is continuously diminishing, the issue of high accuracy measurement becomes increasingly significant. In recent years, Atomic Force Microscopy (AFM) has become a powerful measurement tool which has been widely used in micro- and nano-fabricated structure inspection. However, owing to the fixed tilting angle of the scanning probe in traditional AFM, there generally exists a distorted scanning result at the corner and sidewall of the scanned sample. To mitigate the mentioned problem, this paper presents a self-designed dual-probe AFM system with an on-line adaptive tilting angle algorithm which can estimate the most effective tilting angle for each scanning probe. Above all, a novel probe-tilting mechanism is designed to change the tilting angle after one-line scanning process is accomplished. As a result, a complete and high-precision scanning image can be obtained in a single scan through such dual-probe structure.