Design of High-Sensitivity Cantilever and Its Monolithic Integration With CMOS Circuits

Rectangular piezoresistive cantilevers with stress concentration holes opened were designed and fabricated in order to increase the response signals of piezoresistive cantilever first. Both the simulations and the measurements on the cantilever sensitivity show that this design can obviously result in an improvement on the displacement sensitivity of the piezoresistive cantilever. After a characterization study on the piezoresistive cantilever, a monolithic integration of the microcantilever array with a complementary metal–oxide–semiconductor (CMOS) readout circuitry based on the silicon-on-insulator (SOI) CMOS and the SOI micromachining technologies was designed. A cantilever array, a digital controlled multiplexer, and an instrumentation amplifier compose the integrated sensor system, and post-CMOS process was designed to fabricate the integrated system. The measurement results on the SOI CMOS circuitry of the integrated system prove a feasibility of the integration design.