Microlithography of electron gases formed at interfaces in oxide heterostructures

Submicron wide structures of conducting quasi-two-dimensional electron gases generated at SrTiO3∕LaAlO3 interfaces have successfully been patterned by modulating the thickness of the LaAlO3 layers with unit cell resolution. This technique allows the authors to structure the electron gases without exposing them to the environment and without incorporating other materials at the edges. The structured electron gases have resistances of ≈200Ω∕◻ (4.2K) and mobilities of ≈700cm2∕Vs (4.2K), while the resistances of the areas patterned to be insulating exceed 1010Ω∕◻.