Integration of enhancement/depletion- mode InGaP/InGaAs doped-channel pseudomorphic HFETs for direct-coupled FET logic application

摘要

InGaP/InGaAs-integrated enhancement/depletion-mode doped-channel pseudomorphic HFETs, fabricated on the same chip by a selective etching process, are demonstrated for the first time. For the depletion-mode device, the drain-to-source saturation voltage is only 0.3 V as V_(GS) is fixed at 0 V. An extrinsic transconductance of 411 (278) mS mm~(-1) and a saturation current density of 221 (482) mA mm~(-1) are obtained for the enhancement (depletion) device. Furthermore, the noise margins NM_h and NM_l values are up to 0.731 V (0.72 V) and 0.28 V (0.755 V) at a supply voltage of 1.5 V (2.0 V) in the direct-coupled FET logic application.