Microwave operation of submicrometer channel-length Silicon MOSFET's

Aluminum-gate silicon n-channel MOSFET's with channel lengths down to 0.5 µm have been fabricated. A simple four-mask process based on contact optical lithography was used. Partial self-alignment of the gate to the channel could be achieved because of an enhanced oxidation rate over the source/drain due to the heavy arsenic implantation. Accordingly, parasitics were minimized and the devices showed excellent microwave performance with
f_{\max}
and f
T
near 20 GHz.