Fabrication and characterization of 100-nm In0.53Ga0.47As-In0.52Al0.48As double-gate HEMTs with two separate gate controls

In this letter, we demonstrate successful operation of 100-nm T-gates double-gate high electron mobility transistors with two separate gate controls (V_g1s ≠ V_g2s). These devices are fabricated by means of adhesive bonding technique using enzocyclocbutene polymer. The additional gate enables the variation of the threshold voltage V_th in a wide range from -0.68 to -0.12V while keeping high cutoff frequency f_t of about 170 GHz and high maximum oscillation frequency f_max of about 200 GHz. These devices are considered as being very effective for millimeter-wave mixing applications and are promising devices for the fabrication of velocity modulation transistor (VMT) (Sakaki et al., 1982).