Characteristics of fully quaternary In0.52(Al0.8Ga0.2)0.48As/In0.53(Al0.2Ga0.8)0.47As heterostructures in doped-channel FETs

A fully quaternary In/sub 0.52/(Al/sub 0.8/Ga/sub 0.2/)/sub 0.48/As/In/sub 0.53/(Al/sub 0.2/Ga/sub 0.8/)/sub 0.47/As heterostructure was introduced into doped-channel FETs (fully-Q DCFETs) on InP substrates for the first time. Combining the advantages of high quality quaternary InAlGaAs Schottky and channel layers, the authors were able to enhance device gate-to-drain and channel breakdown voltages, and to eliminate the kink effect. This results in an extremely low output conductance (g/sub 0/=0.6 mS/mm), and a high DC gain ratio (g/sub m//g/sub 0//spl sime/350).