A 1- mu m MODFET process yielding MUX and DMUX circuits operating at 4.5 Gb/s

The authors report a high-yield 1- mu m enhancement- and depletion-mode MODFET (E/D MODFET) process capable of producing medium-scale integrated circuits. Special care has been taken to reduce anomalous transients. Reproducible MBE (molecular-beam epitaxy) growth of epi-layers and a uniform and reproducible RIE (reactive ion etch) process have resulted in excellent threshold voltage (V/sub TH/) control. The standard deviation of V/sub TH/ for EFETs with a median V/sub TH/ value of 0.27 V was 42 mV from wafer to wafer and 21 mV across a wafer. With this process the authors have demonstrated a stand-alone general-purpose 8-bit multiplexer and demultiplexer pair operating at 4.5 Gb/s with a power consumption of 1.4 W and 2.2 W, respectively.<>