Fabrication of sub-100nm dual-gate MODFETS with enhanced performance

A novel dual-gate MODFET structure with two gates (<50 nm long) separated by 50 nm or less has been fabricated on a GaAs/AlGaAs modulation-doped substrate, using standard MODFET fabrication steps and high-resolution electron-beam lithography for all levels. Measurements show that the two gates cannot be treated independently, that the threshold voltage of the device can be tuned by proper biasing the first gate, high transconductance and cutoff frequency can be achieved by tailoring the field distribution under the two gates. © 1991.