Real-Time Control for Two-Dimensional Positioning and Scanning with Nanometer Precision

摘要

The real-time feedback control scheme was adapted to compensate for the nonlinearity, hysteresis, and other deviations of PZT. The PZT served as the fine actuator and the DC-motor as the coarse actuator in the developed system. With the feedback control, the errors in the step and linear tracking of the two-dimensional positioning system were able to achieve the precision of 0.42 nm (rms) and 5 nm (rms), in the 2-mm range, respectively. A VLSI sample, STR3-180, with the measured area of 19.7 nm by 33.3 μm was used as the test piece. The result of the scanning indicated a 1% deviation from the default value of the standard reference.