Antimonide-Based Diodes For Terahertz Mixers

Antimonide-based p(+)N junctions have been grown by molecular beam epitaxy and processed into diodes. The diodes have good rectification with ideality factors near 1, and high saturation current densities of 2.5x10(-2) A/cm(2). S-parameter measurements to 50 GHz indicate a 1 Omega series resistance and a capacitance of 1.2 fF/mu m(2) for a 5 mu m diameter mesa diode. A cutoff frequency of 6.5 THz is estimated from the RC product. The high saturation current indicates that this diode will reach forward bias currents at substantially lower voltages than GaAs Schottky diodes. These properties suggest using the diode as a terahertz mixer. (c) 2008 American Institute of Physics.