Experimental investigation of traps in THz Schottky diodes

In this paper, indications of charge trapping in THz Schottky diodes are investigated with various measurement techniques including current-voltage, capacitance and low-frequency noise measurements. GaAs diodes from various manufacturers are tested. For comparison purposes, results for two different diode samples are presented. Correlation between different measurement techniques is observed which indicate the presence of traps in measured Schottky diode samples. I-V and C-V measurements show some trapping behavior. However, it is also important to observe frequency dependency of the diode capacitance and low-frequency noise properties to closely monitor the charge trapping in small area Schottky diodes. Diode samples are measured in on-wafer environment using a probe station.