ABSTRACT: High-performance inversion-type enhancement-mode n -channel In <sub>0.65</sub> Ga <sub>0.35</sub> As metal-oxide-semiconductor field-effect transistors (MOSFETs) with atomic-layer-deposited Al <sub>2</sub> O <sub>3</sub> as gate dielectric are demonstrated. A 0.5 μ m gate-length MOSFET with an Al <sub>2</sub> O <sub>3</sub> gate oxide thickness of 10 nm shows a gate leakage current less than 5×10<sup>-6</sup> A / cm <sup>2</sup> at 4 V gate bias, a threshold voltage of 0.40 V , a maximum drain current of 670 mA / mm , and transconductance of 230 mS / mm at drain voltage of 2 V . More importantly, a model is proposed to ascribe this 80% improvement of device performance from In <sub>0.53</sub> Ga <sub>0.47</sub> As MOSFETs mainly to lowering the energy level difference between the charge neutrality level and conduction band minimum for In <sub>0.65</sub> Ga <sub>0.35</sub> As . The right substrate or channel engineering is the main reason for the high performance of the devices besides the high-quality oxide-semiconductor interface.
Applied Physics Letters 01/2008; · 3.84 Impact Factor