Fabrication of self-aligned enhancement-mode In0.53Ga0.47As MOSFETs with TaN/HfO2/AlN gate stack

In this letter, we report the fabrication and characterization of self-aligned inversion-type enhancement-mode In0.53Ga0.47As metal-oxide-semiconductor field-effect transistors (MOSFETs). The In0.53Ga0.47As surface was passivated by atomic layer deposition of a 2.5-nm-thick AlN interfacial layer. In0.53Ga0.47As MOS capacitors showed an excellent frequency dispersion behavior. A maximum drive current of 18.5 mu A/mu m was obtained at a gate overdrive of 2 V for a MOSFET device with a gate length of 20 Mm. An I-ON/I-OFF ratio of 10(4), a positive threshold voltage of 0.15 V, and a subthreshold slope of similar to 165 mV/dec were extracted from the transfer characteristics. The interface-trap density is estimated to be similar to 7-8 x 10(12) cm(-2) . eV(-1) from the subthreshold characteristics of the MOSFET.