Extension of the Schottky barrier detector to 70 μm (4.3 THz) using submicron-dimensional contacts

Schottky barrier diode detection in both video and mixing modes of operation has been extended to 4.252 THz (70.5 μm) using 0.5-μm-diam diodes fabricated from heavily doped nonepitaxial n-type GaAs. These ultrasmall, and consequently ultralow capacitance, junctions were prepared using electron-beam lithography and have yielded the smallest reported series-resistance junction-capacitance product for a Schottky barrier diode. The potential for extending diode operation to still higher frequencies is discussed.