A 1-kV, 0.84-kV/ns Epi-Si Drift-Step-Recovery Diode

Drift-step-recovery diodes (DSRDs) are key components in nanosecond and subnanosecond pulsed-power solid-state circuits. The fabrication of a high-voltage (HV) diode is typically a four-layer structure, which requires a lengthy, deep diffusion (10's of micrometer) process. The diode voltage is usually in the range of 300-600 V. In this article, we introduce a three-layer, p ^+ -p-n ^+ , structure, which relies on a thick, 70 \mu m, base by epitaxial growth. This method simplifies the fabrication process and may fit for production at large quantities in regular fabs. We present the design, simulation, and results for a single DSRD die. In the simulation, we show that during the transition of the diode into a nonconducting mode, electrons and holes drift toward the n ^+ and p ^+ regions, respectively, as expected. In the experiment, the measured peak voltage and rise rate into a 50- \Omega load were 1 kV, and 0.84 kV/ns, respectively. These results exceed recent works. A compact design of an HV all-solid-state circuit, which relies on this diode, is presented. The circuit consists of two stages in series of a precharged capacitor and an air coil, followed by two cascaded compression stages, each with a stack of DSRD dies. The output of the DSRD stage, measured over a 50- \Omega load, was 31.6 kV. This pulse was then used to drive two stages of fast-avalanche diodes, resulting in a 28.1-kV, 247-ps rise-time pulse, with a rise rate of 106 kV/ns.