QUANTUM-WIRE TRANSISTOR AT LOCALLY GROWN EDGES

Quantum wires are conventionally realised with either high resolution lithography or with a complex process sequence involving many critical steps. In this work we report, for the first time, realisation of qua ntum wire transistors at locally grown edges, using molecular beam epi taxy (MBE) through micro shadow masks. This method does not require hi gh resolution lithography and simplifies the fabrication process. The fabricated devices were electrically characterised at room temperature and at liquid helium temperature for different applied magnetic field strengths. Oscillations are observed in the input characteristic at l iquid helium temperature. The magnetic field dependence of these oscil lations and Shubnikov-de Haas oscillations indicates, that quantum wir es with an effective width of 50 nm are realised due to field effect a t the locally grown edges. (C) 1998 Elsevier Science S.A. All rights r eserved.