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

An integrated micro positioning xy-stage with a 2 mm × 2 mm-area shuttle is fabricated for application in nanometer-scale operation and nanometric positioning precision. It is mainly composed of a silicon-based xy-stage, electrostatics comb actuator, and a displacement sensor based on a vertical sidewall surface piezoresistor. They are all in a monolithic chip and developed using double-sided bulk-micromachining technology. The high-aspect-ratio comb-driven xy-stage is achieved by deep reactive ion etching (DRIE) in both sides of the wafer. The detecting piezoresistor is located at the vertical sidewall surface of the detecting beam to improve the sensitivity and displacement resolution of the piezoresistive sensors using the DRIE technology combined with the ion implantation technology. The experimental results verify the integrated micro positioning xy-stage design including the micro xy-stage, electrostatics comb actuator, and the vertical side-wall surface piezoresistor technique. The sensitivity of the fabricated piezoresistive sensors is better than 1.17 mV/μm without amplification and the linearity is better than 0.814%. Under 30V driving voltage, a ±10μm single-axis displacement is measured without crosstalk and the resonant frequency is measured at 983Hz in air.