Design and Fabrication for High-Voltage Silicon Carbide Drift Step Recovery Diode

A high-voltage drift step recovery diode (DSRD) based on silicon carbide (SiC) with a 6.2 kV blocking voltage of a single die is reported in this paper. The design and fabrication process of the SiC DSRD are also included. The bulk structure parameters of the high-voltage SiC DSRD and the termination structure parameters of a 3-step etched junction termination extension (JTE) are determined by the TCAD simulation. A pulse test circuit based on the high-voltage DSRD is designed. A high voltage pulse with a rise time of 0.8 ns and an amplitude of 5 kV is obtained through the TCAD simulation. In order to meet the expected blocking capability, the termination preparation process including the etching sequence of multi-step structure and the microtrench in inductively coupled plasma (ICP) etching of SiC is mainly investigated. The test results show that the sample can block a reverse voltage of 6.2 kV as a single die with a leakage current of $1.3 \mu A$ at room temperature. In addition, the specific ohmic contact resistance of the anode calculated by C-TLM method is $1.56 \times 10^{-6} \Omega \cdot$ cm2.