III-Sb Interfaces with High-k Oxides: Science and Technology of Novel MOSFET Gate Stack

Technical: Metal-oxide-semiconductor field-effect transistors (MOSFETs) based on group III-V semiconductors have significant potential advantages over silicon-based devices for high-speed, low-power digital integrated circuits. MOSFETs with group III-Sb channels could reduce the switching energy-delay product by an order of magnitude. This project studies gate stacks for scalable n- and p-type MOSFETs with low interface state density and superior channel transport using a novel material system: high dielectric constant (k) oxide on In(Ga)Sb quantum-well channel. The research involves in-situ passivation of III-V channels grown using molecular beam epitaxy in an ultrahigh vacuum environment followed by an in-situ deposition of high-k oxide. A few-monolayer-thick amorphous Si or Al serves as the interface passivation layer and is incorporated into the high-k stack based on HfO2 or other high-k oxides. This approach is expected to reduce interface state density, improve thermal stability, and reduce carrier scattering. Non-technical: The project addresses basic research issues in a topical area of materials science with high technological relevance. Significant impacts are expected on the microelectronic industry through technology development, commercialization, and the facilitation of further scaling of digital circuits thus providing better, higher quality and less expensive electronics. The project also contributes to education activities through graduate student training, undergraduate minority student participation of research, and promotion of science and technology to the general public.