MEMS transistor integrated on CMOS

PORTLAND, Ore.—A micro-electro-mechanical system (MEMS) transistor was announced by Semiconductor Research Corp. (SRC) and Cornell University, giving SRC members access to on-chip timing solutions for their CMOS chips.

The MEMS-JFET builds a junction field-effect transistor (JFET) on top of a silicon resonator, providing both amplification and a rock-solid mechanical reference for on-chip channel-select filters and oscillators.

"We believe that this research result will allow the direct integration of radio frequency sources onto silicon chips alongside all the other CMOS circuitry," said Kwok Ng, senior director of device sciences at SRC.

The process works by integrating the MEMS and JFET structures on a silicon-on-insulator (SoI) substrate using conventional CMOS processes. Sacrificial oxides are then etched from beneath the single-crystal silicon resonator leaving it suspended. Using a p-n junctions as the transducer, the JFET can be made to oscillate at a frequency determined by the dimensions of the suspended MEMS resonator.


Junction field-effect transistor (JFET) built on a silicon resonator provides both amplification and a rock-solid mechanical reference for on-chip channel-select filters and oscillators.

MEMS transistor integrated on CMOS