Investigation of Prepulse of SiC Drift Step Recovery Diode in Fast Interruption Process

• Published in: IEEE transactions on electron devices Vol. 71; no. 5; pp. 3102 - 3108
• Main Authors: Yan, Xiaoxue, Liang, Lin, Yang, Zewei, Shang, Hai
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.05.2024; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Drift; Drift step recovery diode (DSRD); Electric potential; High-voltage techniques; Load resistance; opening switch; power semiconductor diode; prepulse; Pulse generation; Recovery; Semiconductor diodes; Silicon; Silicon carbide; silicon carbide (SiC); Step recovery diodes; Switches; Voltage
• ISSN: 0018-9383; 1557-9646
• DOI: 10.1109/TED.2024.3379959

The output pulse voltage with a front of high dV/dt is an important feature in the application of silicon carbide (SiC) drift step recovery diodes (DSRDs). However, the presence of prepulse leads to a deformation of the pulse front, reducing its mean rising rate. The influence factors and mechanisms of prepulse of 4H-SiC DSRD are investigated in this article. <inline-formula> <tex-math notation="LaTeX">\eta </tex-math></inline-formula> is proposed to evaluate the prepulse characteristics, which is defined as the ratio of the prepulse amplitude (<inline-formula> <tex-math notation="LaTeX">{V}_{\text {pre}}{)} </tex-math></inline-formula> to the peak output voltage (<inline-formula> <tex-math notation="LaTeX">{V}_{\text {peak}}{)} </tex-math></inline-formula>. A good output characteristic should have a low <inline-formula> <tex-math notation="LaTeX">\eta </tex-math></inline-formula>. The experimental results indicate that the device area (<inline-formula> <tex-math notation="LaTeX">{S}{)} </tex-math></inline-formula>, power supply voltage (<inline-formula> <tex-math notation="LaTeX">{V}_{\text {cc}}{)} </tex-math></inline-formula>, and load resistance (<inline-formula> <tex-math notation="LaTeX">{R}_{\text {load}}{)} </tex-math></inline-formula> have a significant impact on the prepulse. Through Sentaurus TCAD simulation, the effects of the three factors on prepulse were further obtained over a larger range of variations. The simulation results agree with the experimental data well. The results indicate that <inline-formula> <tex-math notation="LaTeX">{V}_{\text {pre}} </tex-math></inline-formula> does not depend on <inline-formula> <tex-math notation="LaTeX">{V}_{\text {peak}} </tex-math></inline-formula>. Increasing <inline-formula> <tex-math notation="LaTeX">{S} </tex-math></inline-formula>, <inline-formula> <tex-math notation="LaTeX">{R}_{\text {load}} </tex-math></inline-formula>, and <inline-formula> <tex-math notation="LaTeX">{V}_{\text {cc}} </tex-math></inline-formula> can all reduce <inline-formula> <tex-math notation="LaTeX">\eta </tex-math></inline-formula>, but only an increase in <inline-formula> <tex-math notation="LaTeX">{S} </tex-math></inline-formula> can reduce <inline-formula> <tex-math notation="LaTeX">{V}_{\text {pre}} </tex-math></inline-formula> among the three factors. From the perspective of prepulse characteristics, SiC DSRDs are more suitable for application at higher voltage conditions rather than lower voltage, as there is often a lower <inline-formula> <tex-math notation="LaTeX">\eta </tex-math></inline-formula> under higher voltage conditions.