Novel Materials & Devices

Amorphous oxide semiconductors provide an excellent pathway for building vertically stackable transistors in a monolithic 3D fashion due to low temperature in situ selective area growth and disorder-immune carrier conduction path from strongly overlaping isotropic s-orbitals of metal cations. 

Besides being technologically relevant, AOS also provides an excellent playground for investigating fundamental materials and device physics. We are interested in answering fundamental questions such as: How structural disorder impacts carrier transport and mobility? How tuning the atomic arrangements can impact the metal-oxygen polyhedral networks? How different metal-oxygen polyhedra arrangements impact defect density and carrier transport? How can mathematical tools such as topological data analysis and persistent homology reveal hidden order in a disorder materials?

We are interested in harnessing the polar orthorhombic phase in doped Hafnium Oxide systems through stoichiometric composition, strain engineering, deposition and post-deposition treatments such as crystallization anneals. By incorporating such ferroelectric oxide into the gate dielectric of a conventional logic transistor (both Silicon as well as non-Silicon), we can realize an ultra-dense single transistor ferroelectric memory. Moreover, by using the amorphous oxide semiconductor as a channel material over such ferroelectric gate oxide allows the relaization of a vertically stackable monolithic 3D memory. We are ineterested in exploring fundamental questions such as: How can we lower the energy barrier between stabilized polarization states using multi-cation co-doping? How can we leverage exotic topological features such as domain walls, vortices, skyrmions and novel phenomena such as quantum fluctuations and phase-transitions for new memory and neuromorphic computing?