Silicon carbide SiC semiconductor devices have become popular due to their excellent characteristics - these devices have wide bad gaps, high thermal conductivity, and high critical electric field. These devices are suitable for high temperature, high pressure, and high power applications. These characteristics also reduce power consumption and increase the efficiency of the device. These are the reasons why these devices are also popular in the aerospace and space industry. In previous research it has been shown that the SiC are susceptible to radiation damage and single-event burnouts (SEB). This paper provides a design proposal for a new 4H-SiC JBS schottky device that has increased resistance to SEB. The main idea behind the newly proposed design is to reduce the doping concentration and decrease the electric field intensity and impact generation rate at the PN and N-/N+ junctions. The SEB are directly related to thermal breakdowns within the devices because as high energy particles in the space environment passes through the junctions of the semiconductor, it causes movement of charge carriers, which is effectively a current within highly resistive material leading to large heat generation.
The performance of the proposed design was simulated and results presented in the paper. The thermal characteristics of the proposed design improved when compared to conventional 4H-SiC JBS device, but the basic electrical characteristics were slightly worse. The breakdown voltage of conventional device at 300K was around 2090 V, but the in the new design the breakdown voltage was 1534 V. However, this was within the expected results. Also the breakdown temperature was studied as the particle moving through the semiconductor material was simulated. 3100 K was set as the temperature at which the SEB will occur. From the performed simulations the proposed design shown that the temperatures within the material remain below the 3100 K threshold, but the conventional methods well exceed it. Currents also were simulated within the materials, and the proposed design experienced lower current peaks within the non-conductive material. Considering that multiple layer doping were used, there are quite a noticeable amount of parameters that can be studied and changed, which was another focus of the paper - find parameters that give the best results.
The paper proposed an effective design for SiC schottky diodes, which was verified using the TCAD software. The proposed material configuration was irradiated with high energy particles under reverse bias voltage. The maximum experienced temperature in the material was 2817 K, which is below the 3100 K - breakdown temperature of the SiC material.
Papers:
- M. -B. Li, F. Cao, H. -F. Hu, X. -J. Li, J. -Q. Yang and Y. Wang, "High Single-Event Burnout Resistance 4H-SiC Junction Barrier Schottky Diode," in IEEE Journal of the Electron Devices Society, vol. 9, pp. 591-598, 2021, doi: 10.1109/JEDS.2021.3084797
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