Performance and modeling of antimonide-based heterostructure backward diodes for millimeter-wave detection

Heterostructure backward diodes have been fabricated and characterized for use as zero-bias millimeter-wave detectors. Sensitive detector performance in the W-band was achieved by scaling the active area to 1.5×1.5 μm² through the use of high-resolution i-line stepper lithography. Responsivities of 2450 V/W and 2341 V/W were measured on-wafer at 95 GHz and 110 GHz, respectively. The detectors exhibit good detection linearity, with 0.8 dB compression, measured at an RF power of 4 μW at 95 GHz. A nonlinear device model, based on bias-dependent millimeter-wave S-parameter measurements, has been developed. The model is consistent with the measured frequency response, responsivity, and detector compression characteristics. Extrapolation using the model to reduced device dimensions suggests that this device technology should provide appreciable responsivities (>1000 V/W) at frequencies through G-band and beyond.