The role of contact size on the formation of Schottky barriers and ohmic contacts at nanoscale metal-semiconductor interfaces

We have measured the electronic structure at Au nanoisland - niobium doped SrTiO ₃ interfaces over a range of contact diameters. Electron transport processes at the interface transition from thermionic emission dominated to tunneling dominated, leading to ohmic behavior at small sizes. The transition increases at a much higher rate than is generally expected, emphasizing the need for precise control of nanoscale dimensions for reproducible effects in nanoscale electronic devices.