30 nm In0.7Ga0.3As Inverted-Type HEMTs with reduced gate leakage current for logic applications

We have fabricated 30 nm In0.7Ga0.3As Inverted-Type HEMTs with outstanding logic performance, scalability and high frequency characteristics. The motivation for this work is the demonstration of reduced gate leakage current in the Inverted HEMT structure. The fabricated devices show excellent Lg scalability down to 30 nm. Lg = 30 nm devices have been fabricated with exhibit gm = 1.27 mS/µm, S = 83 mV/dec, DIBL = 118 mV/V, ION/IOFF = 4 × 10⁴, all at 0.5 V. More significantly, the removal of dopants from the barrier suppresses forward gate leakage current by over 100X when compared with equivalent normal HEMTs. The Lg = 30 nm devices also feature record high-frequency characteristics for an inverted-type HEMT design with fT = 500 GHz and fmax = 550 GHz.