Development of a Leakage Current Measurement System for Semiconductor Detectors

In this article, we examine a high-precision leakage current measurement system with a semiconductor detector and automatic range switching. The system consist of two main modules: the leakage current measurement module and the control and display module. The leakage current measurement module is based on the transresistance amplifier principle and builds an I-V conversion circuit. A large measuring range from nA to pA is achieved through range switching via a relay-controlled mechanism. The control and display module has an automatic range switching algorithm developed using the STM32 microprocessor. This algorithm accurately measures the leakage current of the semiconductor detector by controlling the relay via the GPIO port. In addition, a detector detection platform is set up to judge whether the detector has been damaged based on the measured leakage current data. The system designed in this paper can measure leakage currents ranging from 1 pA to 2000 nA with a margin of error of less than 0.32%. Its performance has been successfully validated with a variety of detectors.