Highly doped InGaP/InGaAs/GaAs pseudomorphic HEMT's with 0.35 micron gates

We fabricated 0.35-micron gate-length pseudomorphic HEMT DCFL circuits, using a highly doped thin InGaP layer as the electron supply layer. The lnGaP/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 micron. We obtained a K value of 555 mS /Vmm and a transconductance g(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 V(DD) of 1 V, and 13.8 ps and 2.2 fJ at V(DD) of 0.6 V for gates 10 microns wide. (Author)