Highly doped InGaP/InGaAs/GaAs pseudomorphic HEMT's with 0.35 /spl mu/m gates

We fabricated 0.35-/spl mu/m gate-length pseudomorphic HEMT DCFL circuits using a highly doped thin InGaP layer as the electron supply layer. The InGaP/InGaAs/GaAs pseudomorphic HEMT grown by MOVPE is suitable for short gate-length devices with a low supply voltage since it does not show short channel effects even for gate length down to 0.35 /spl mu/m. We obtained a K value of 555 mS/Vmm and a transconductance g/sub m/ of 380 mS/mm for an InGaP layer 18.5 nm thick. Fabricated 51-stage ring oscillators show the basic propagation delay of 11 ps and the power-delay product of 7.3 fJ at supply voltage of V/sub DD/ of 1 V, and 13.8 ps and 3.2 fJ at V/sub DD/ of 0.6 V for gates 10 /spl mu/m wide.<
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