A technology for monolithic MEMS-CMOS integration and its application to the realization of an active-matrix tactile sensor

Presently described is an application of a technology based on the surface-migration of silicon for the monolithic integration of micro-mechanical devices and complementary metal-oxide-semiconductor (CMOS) electronic circuits. A cavity sealed with a cover-diaphragm is first formed without a sacrificial layer etch. The electronic devices are next fabricated. The issues of material- and process-incompatibility inherently present in many integration schemes are largely avoided. A 16×16 active-matrix tactile sensor integrating 256 force-sensing diaphragms, 512 pixel transistors and 512 piezoresistors was designed, realized and characterized. The spatial resolution of the sensor was ~145 “pixels per inch” and the pressure sensitivity was ~0.07 μV/V/Pa.