High-Frequency Performance of Self-Aligned Gate-Last Surface Channel $\hbox {In}_{0.53}\hbox {Ga}_{0.47}\hbox {As}$ MOSFET

We have developed a self-aligned L_g = 55 nm In_0.53Ga_0.47As MOSFET incorporating metal-organic chemical vapor deposition regrown n⁺⁺ In_0.53Ga_0.47As source and drain regions, which enables a record low on-resistance of 199 Ωμm. The regrowth process includes an InP support layer, which is later removed selectively to the n⁺⁺ contact layer. This process forms a high-frequency compatible device using a low-complexity fabrication scheme. We report on high-frequency measurements showing f_max of 292 GHz and f_t of 244 GHz. These results are accompanied by modeling of the device, which accounts for the frequency response of gate oxide border traps and impact ionization phenomenon found in narrow band gap FETs. The device also shows a high drive current of 2.0 mA/μm and a high extrinsic transconductance of 1.9 mS/μm. These excellent properties are attributed to the use of a gate-last process, which does not include high temperature or dry-etch processes.