Temperature-dependent characteristics of enhancement-/depletion-mode double δ-doped AlGaAs/InGaAs pHEMTs and their monolithic DCFL integrations

摘要

The enhancement-mode (E-mode) and depletion-mode (D-mode) device operations on the same chip and their monolithic integration to form a DCFL inverter by using the double δ-doped AlGaAs/InGaAs pseudomorphic high-electron-mobility transistors have been successfully fabricated and investigated. Distinguished static and microwave-frequency characteristics of the E-mode and D-mode pHEMTs at high ambient temperatures and the temperature-dependent performances of the monolithic DCFL gate integration have been comprehensively studied. Experimentally, the studied device demonstrates superiorly stable thermal threshold coefficient (partial derivV_(th)/ partial derivT) of 1 (—1.27) mV/mm-K for the D-mode (E-mode) device. The noise margins of the DCFL inverter, at V_(DD) = 1V, are superiorly maintained above 0.1 V as the ambient temperature increases up to 400 K. The present devices are promisingly suitable for the low-power-dissipation, high-temperature digital circuit or the mixed-mode circuit applications.