Sidewall spacer defined resonant interband tunneling diodes

We report on a contacting and fabrication scheme for a sub-500 nm InAs/AlSb/GaSb resonant interband tunneling diode (RITD) without using any fine-line lithography. Epitaxial regrowth on patterned substrates combined with sidewall spacer technology is used to define the device dimensions. During regrowth, the crystal facet termination obtained by choosing the appropriate orientation for the device is utilized to make electrical contact to the device in the desired directions and to isolate the device in all other directions. The concept, fabrication process, current-voltage characteristics of the device, and a comparison with RITDs fabricated in a conventional manner are reported.