High speed-low power GaAs/AlGaAs TEGFET integrated circuit

Two-dimensional electron gas FETs (TEGFETs) have been used to fabricate DCFL circuits. The MBE wafers are processed as-grown without any recessed gate etching nor self-aligned implantation. Source, drain and gate are directly deposited on the wafer to realize enhancement-mode FETs whereas loads are ungated transistors. With delay times of 18.4 and 32.5 ps at 300 K for 0.9 and 0.032 mW respectively, TEGFETis the fastest semiconductor device amd present very low power dissipation. It is shown that these performances are still limited by contact resistance and material quality. Improvements of these parameters will lead to delay time of ∼9 ps at 300 K for 0.7 m gate length. The high performance and the simplicity of the process involved, make the TEGFET very suitable for LSI/VLSI applications.