Field-Effect Transistors with Submicrometer Gate Lengths Fabricated from LAO-STO-Based Heterostructures
Due to their wide spectrum of functionalities, complex oxides are highly interesting for use in electronic devices. We have fabricated and analyzed very small field effect transistors (FETs) built from complex oxides and explored the possible existence of short-channel effects. For this we studied devices with various gate lengths fabricated from LaAlO3-SrTiO3 heterostructures.
Using a highest-standard epitaxial deposition system and state-of-the-art electron beam lithography, we succeeded in fabricating FETs with gate lengths as small as 60 nm. Short-channel effects comparable to those known from semiconductors were observed for devices with gate lengths smaller than 1 µm. Due to the fundamentally different operation principles, theoretical methods for describing semiconductor physics are applicable only with considerable restrictions. This work paves the way for further experimental investigation of complex-oxide devices with critical feature sizes of a few 10 nm and encourages theoretical work for a better understanding of these systems.
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