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Next: 6. Transistor Characterization Up: 5.4 Technologies Under Investigation Previous: 5.4.7 Technology G: Enhancement Mode

5.4.8 Technology H: AlGaN/GaN HEMTs

Al$ _x$Ga$ _{1-x}$N/GaN based HEMT structures are shown for experimental comparison. The layers are based on a MOCVD growth process on sapphire substrates with a gate length down to $ {\it l}_{\mathrm{g}}$= 200 nm. Typical Al concentrations are $ x$= 0.25 in the barrier. In contrast to Fig. 3.1 single heterojunction devices are processed.