A silicon integrated micro nano-positioning XY-stage for nano-manipulation

An integrated micro XY-stage with a 2 x 2 mm(2) movable table is designed and fabricated for application in nanometer-scale operation and nanometric positioning precision. The device integrates the functions of both actuating and sensing in a monolithic chip and is mainly composed of a silicon-based XY-stage, comb-drive actuator and a displacement sensor, which are developed by using double-sided bulk-micromachining technology. The high-aspect-ratio comb-driven XY-stage is achieved by deep reactive ion etching (DRIE) on both sides of the wafer. The displacement sensor is formed on four vertical sidewall surface piezoresistors with a full Wheatstone bridge circuit, where a novel fabrication process of a vertical sidewall surface piezoresistor is proposed. Comprehensive design and analysis of the comb actuator, the piezoresistive displacement sensor and the XY-stage are given in full detail, and the experimental results verify the design and fabrication of the device. The final realization of the device shows that the sensitivity of the fabricated piezoresistive sensors is better than 1.17 mV mu m(-1) without amplification, and the linearity is better than 0.814%. Under 28.5 V driving voltage, a +/- 10 mu m single-axis displacement is measured without crosstalk and the resonant frequency is measured at 983 Hz in air.