50 nm InP high electron mobility transistors
A new type of field-effect transistor (FET), the indium phosphide high electron mobility transistor (InP HEMT), has recently emerged as an attractive candidate for low noise applications at microwave and MM-wave frequencies. It exhibits the lowest noise figures (<1 dB at 60 GHz), and the highest cutoff frequencies (>300 GHz) among all three-terminal semiconductor devices. Also, it is the only type of transistor that has shown useful gain at frequencies above 100 GHz (7.3 dB at 140 GHz). The authors describe the scaling of InP HEMTs down to 50 nm gate length. By properly designing the HEMT epitaxial layer and scaling its parasitic resistances, significant improvements in device performance are possible for FETs with gate lengths as short as 50 nm. With further optimization, 50 nm InP HEMTs should extend the operating frequency of three-terminal semiconductor devices to at least 300 GHz, as well as provide a low cost alternative to ultra low noise masers and SIS mixers at microwave frequencies
