Thin-film field-effect transistors based on La-doped SrTiO3 heterostructures

Abstract

Field-effect transistors have been fabricated from epitaxial perovskite strontium titanate heterostructures. Lanthanum-doped SrTiO3 was used as the semiconducting channel while insulating SrTiO3 was used as a gate insulator. Both depletion and accumulation effects in the channel have been studied from 300 to 4 K. Hall effect measurements indicate a temperature independent n-type carrier density around 5×1019 cm−3. At 300 K, typical mobilities are 2–3 cm2 V−1 s−1 while low temperature mobilities are as high as 15 cm2 V−1 s−1.