60 nm gate-length Si/SiGe HEMT

We fabricated n-channel Si/SiGe high electron mobility transistors (HEMTs) with a T-shaped Schottky-metal gate whose length was down to 60 nm. dc measurements showed that the 60 nm gate device had good pinch-off behavior, and its maximum transconductance was 156 mS/mm. RF measurements of the 60 nm gate device showed a current gain cutoff frequency of 52 GHz and a maximum oscillation frequency of 112 GHz. The gate-length dependence of the device characteristics was also discussed. The 60 nm gate is the shortest one ever reported so far for Si/SiGe HEMT.