High Performance Heterostructure Low Barrier Diodes for Sub-THz Detection

Heterostructure low barrier diodes (HLBD) based on lattice-matched AlGaInAs triangular barrier have been designed, fabricated, and characterized for zero-bias millimeter-wave and submillimeter-wave detection. Detectors with different barrier height and various active areas have been measured in order to determine the best structure for low-level radiometric detection. Unmatched responsivity of 1500-2000 V/W have been measured around 100 GHz with a video resistance of 400 to 800 Ω. Thanks to these low-impedances high-matched responsivity of 6000 and 5200 V/W have been demonstrated around 90 and 180 GHz, respectively, with a bandwidth of 25 GHz. Avery low noise equivalent power of about 0.6 and 0.7 pW/,/Hz have been deduced at 90 and 180 GHz, respectively. We show also that the dynamic range of these detectors is more than six decades. This performance makes the HLBD an interesting device for low-level sub-THz detection applications.