Cc. Andrews et al., FABRICATION OF A NANOSCALE, INPLANE GATED QUANTUM-WIRE BY LOW-ENERGY ION EXPOSURE, Journal of vacuum science & technology. B, Microelectronics and nanometer structures processing, measurement and phenomena, 12(1), 1994, pp. 8-13
The fabrication of a nanoscale gated quantum wire in a GaAs modulation
doped field effect transistor substrate is described. Both the wire c
onduction channel, with a 110 nm physical width, and the gates were pa
tterned into the two-dimensional electron gas of the substrate. This s
cheme produced in-plane gated devices with 110 nm gate lengths and 75
nm separations between the active areas. Electron-beam lithography was
used to define masks for a subsequent flood exposure step with low en
ergy argon ions (150 eV). This ion exposure technique produced very hi
gh gate-to-wire isolation, typically greater than 10(14) OMEGA at 4.2
K. The in-plane design employed here drastically reduces gate capacita
nce compared with metal top-gate designs, and promises ultrafast switc
hing times. These devices showed no short channel punch-through effect
s, exhibited low gate leakage, and had sufficient gain to permit integ
ration of several such devices into more complex circuits such as logi
c gates.