Validation of Fast Current Interruption Mechanism in Sub-Nanosecond High-Voltage Switching Diodes

摘要

The fast current interruption property of drift step recovery diodes (DSRDs) is utilized in high-voltage fast switches. Previously, using a physical device simulator, we have conducted a theoretical investigation of this mechanism in a p+πn+ structure and evaluated the expected dependence of device performances on its structure and driving conditions. In this letter, we experimentally validate these findings by presenting consistency between the theoretical results and the actual measured results. Diode structures with a uniform doping profile and abrupt junction were fabricated using thick layer epitaxy technology, which allows for improved control over the doping profile, compared with the traditional method of deep aluminum diffusion. The switching characteristics of the diodes were measured using a specially designed circuit. An outstanding switching time of 0.3 ns at 230 V per DSRD die was demonstrated by driving the diode with a reverse current density exceeding 1250 A/cm2. We conclude that a semi-empirical design of the diode and its driving conditions can be substituted by accurate modeling using the device simulator. By combining the physical understanding gained with accurate modeling capabilities and epitaxial growth technology, novel diode design and improved switching performance may be achieved.