Quantum anti-dot arrays and quantum wire transistors fabricated on heterostructures

We report on a new fabrication process of anti-dot and multiple quantum wire transistors based on InAs/AlGaSb heterostructures with conventional photolithography and wet chemical etching. Starting from the square arrays of a mask, anti-dot arrays of circular shape were fabricated utilizing the unique etching properties of this material system, which are quite different from those of its counterpart GaAs/AlGaAs. Successful formation of the anti-dot structures was confirmed by magnetotransport measurements. For the fabrication of multiple quantum wire transistors, we introduced a GaAs regrowth as a hole barrier between the gate electrode and the InAs channel layer to eliminate the inherent gate leakage current for this material system and to obtain good device performance. By optimizing the fabrication process, we succeeded in forming quantum wires with a width as narrow as 100 nm. The device performance of the quantum wire transistor is compared with that of conventional two-dimensional electron gas transistors.