PORTLAND, Ore. The world's first microelectromechanical systems (MEMS) directly integrated onto a CMOS chip is the aim of a new joint effort among U.S. laboratories, industry and academia.
Advanced Diamond Technologies Inc. (ADT), a spinoff from the U.S. Energy Department's Argonne National Laboratory, partnered last week with MEMS pioneer Innovative Micro Technology (Santa Barbara, Calif.) and the University of Wisconsin at Madison. They will supply the Defense Advanced Research Projects Agency (Darpa) with RF MEMS oscillators and resonators by next year.
MEMS devices will be integrated with CMOS chips using the ultrananocrystalline diamond thin films patented by Argonne National Laboratory and licensed to ADT. Low-temperature processing required for diamond films enables MEMS circuit components to be fabricated in predesignated areas on finished CMOS chips.
"We call our process MEMS-on-CMOS because, today, if you want to add a MEMS device to your CMOS chip, you have to make two chipsone CMOS and one MEMSand bond them together," said ADT President Neil Kane. "We can add diamond MEMS devices to any CMOS chip while its being fabricated."
The Darpa Phase II program is being funded at $1.4 million for one year. The partners will then deliver prototype chips with a MEMS resonator and oscillator fabricated alongside CMOS circuitry. The Wisconsin researchers will use atomic force microscopy tools to characterize the MEMS device's performance.
If the prototype proves successful, Darpa would likely fund a third and final phase.
The prototype device will aim for a modest 100-MHz benchmark, but MEMS oscillators made from ultrananocrystalline diamond should be able reach 3 GHz within a few years, according to John Carlisle, ADT's CTO.
Carlisle said commercialization of diamond is also being driven by cost since it is cheaper. The technique could also help designers add venerable quartz crystal oscillators that sell for 50 cents directly to chips.
Market researcher Gartner estimates the annual market for quartz crystals is about $1 billion. Recently, SiTime Corp. began offering MEMS oscillator chips that are pin-for-pin compatible with quartz crystal oscillator chips.