N. Iredale et al., FORMATION OF NARROW CHANNELS USING SPLIT BACK-GATES DEFINED BY IN-SITU FOCUSED ION-BEAM LITHOGRAPHY, Semiconductor science and technology, 12(1), 1997, pp. 137-139
We have fabricated high electron mobility transistors incorporating sp
lit back-gates using the technique of in situ focused ion beam lithogr
aphy and molecular beam epitaxial regrowth. We show that it is possibl
e to form quasi-ballistic channels by biasing the split back-gate and
have succeeded in defining wires of 400 nm width. Application of a sma
ll perpendicular magnetic field has allowed us to demonstrate that bou
ndary scattering in these devices is mostly specular, as for conventio
nal structures fabricated with Schottky gates.