The Schottky-collector resonant-tunnel-diode (SRTD) is an resonant-tun
nel-diode with the normal N+ collector layer and ohmic contact replace
d by direct Schottky contact to the space-charge layer, thereby elimin
ating the associated parasitic series resistance R(s). By scaling the
Schottky collector contact to submicron dimensions, the device periphe
ry-to-area ratio is increased, decreasing the periphery-dependent comp
onents of the parasitic resistance, and substantially increasing the d
evice's maximum frequency of oscillation. We report measured d.c. and
microwave parameters of planar SRTDs fabricated with lum-geometries in
AlAs/GaAs.