RFμP™ MESFET Fabrication Overview

RFuP technology can be fabricated on any SOI CMOS process. We have currently demonstrated it down to the 32nm node and it consistently shows breakdown voltages greater than ten times the nominal CMOS. Usually, it is more than 20 times higher.

The transition frequency (fT) and maximum oscillation frequency (fmax) have been measured and are >30GHz for the scaled technologies. These numbers are process and geometry dependent.

Process nodes the technology has been demonstrated on include:

Process Status In Development Ready
32 nm SOI Development X
45 nm SOI Demonstrated X
150 nm SOI Demonstrated X
250 nm SOS Demonstrated X
350 nm SOI Demonstrated X

RFμP™ MESFET Performance and Modeling

The plot below shows a sample plot of the RFμP™ technology fabricated on a 45nm process. The blue circles are measurements and the black line is an industry standard model. We have developed both TOM3 and Angelov-Chalmers models for the MESFETs.

The red line represents an approximate breakdown voltage for a single MOSFET on the same technology

FOC and Model

The technology works well on both fully depleted and partially depleted fabrication technologies.  RF Micropower in conjunction with parent company SJT Micropower has pioneered the development of this technology at many different foundries.

A comparison of the RFμP™ MESFET vs MOSFET:

Threshold Voltage, Vth Enhancement mode
e.g. Vth = +0.6V for
Depletion mode
e.g. Vth = -0.5V for N-MESFET
The availability of depletion mode devices alongside traditional enhancement mode devices allows for greater flexibility in circuit design
Conduction Type Minority carrier, inversion channel Majority carrier, depletion channel MESFET does not suffer from floating body effects such as the kink effect. It does not require the body-tie contacts often used as part of SOI CMOS.
Self-aligned Yes No The extended drift region from the gate to the drain (LaD) gives the MESFET a high breakdown voltage.
Gate Material Metal-Oxide-Semi Metal Silicide The Schottky gate of the MESFET can support significant current flow. It is tolerant of high voltage excursions, radiation and wide temperature variations