The CAP-FET, a scaleable MEMS sensor technology on CMOS with programmable floating gate

Abstract

A new MEMS sensor architecture is presented that converts mechanical displacement of a conductive diaphragm directly to a current. The electrical bias on the mechanical element is capacitively coupled to an electrically floating MOS gate that controls the sensor output current. The sensor is manufactured using a process module that slots directly in to a CMOS process. Both the sensor architecture and process module will scale with shrinking CMOS generations. Injection of charge onto the floating gate can be used to program the sensor threshold voltage. The sensor architecture has been demonstrated as a pressure sensor on a CMOS process.