Monolithic integration of InAlAs/InGaAs enhancement and depletion (E/D)-mode metamorphic HEMTs on GaAs substrate

Except for a few studies on enhancement (E)-mode metamorphic HEMTs, most of the research studies so far however focused on depletion (D)-mode HEMTs. In view of excellent performance of D-mode devices, it is compelling to investigate E-mode devices as well. Moreover, once discrete devices are established, it becomes very much interesting to look into the monolithic integration of E- and D-mode devices as it finds an extensive application for ultra-high speed and low power digital circuits. To the best of our knowledge, there are no published results on monolithic integration of metamorphic E/D HEMTs so far. In this paper, we present results on monolithically integrated metamorphic In/sub 0.52/Al/sub 0.48/As/In/sub 0.53/Ga/sub 0.47/As E/D HEMTs on GaAs substrate with gate-lengths down to 0.13 /spl mu/m.