Design Impact on the Static and Short-Circuit Characteristics of SiC-SIT with Non-Uniformly Doped Channel

Abstract:

The static characteristics and short-circuit capabilities of SIT (Static Induction Transistor) depend strongly on its channel design. Analysis show that the doping concentration and the width of the channel are crucial parameters in determining the specific on-resistance, threshold voltage and saturation capabilities of the device. Classically SIT is designed with a uniformly doped channel. Improving the saturation capability of such a device comes along with increasing its on resistance. This drawback can be overcome by using non-uniformly doped channel. This paper shows that this technique achieves a 12.3% decrease in saturation current without changing its on-resistance compared to uniformly doped channel case. This result allows a significant increase of 31% in terms of short-circuit withstanding time of SIT.

• Periodical: Materials Science Forum (Volume 858)
• Pages: 925-928
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.858.925
• Online since: May 2016
• Authors: Shi Qin Niu*, Maxime Berthou, Dominique Tournier
• Keywords: Channel Geometry, Short Circuit Characteristics, Silicon Carbide (SiC), Static Circuit Characteristics, Static Induction Transistor (SIT)

References

[1] P. Friedrichs, R. Rupp, Silicon carbide power devices-Current developments and potential applications, Power Electron. Appl. 2005 Eur. Conf., 2015, pp.1-11.

DOI: 10.1109/epe.2005.219736

[2] R. Tanaka, et al., Impact of grounding the bottom oxide protection layer on the short-circuit ruggedness of 4H-SiC trench MOSFETs, Power Semiconductor Devices & IC's (ISPSD), 2014, pp.75-78.

DOI: 10.1109/ispsd.2014.6855979

[3] G. Romano, et al., Short-circuit Failure Mechanism of SiC Power MOSFETs, Power Semiconductor Devices & IC's (ISPSD), 2015, pp.345-348.

DOI: 10.1109/ispsd.2015.7123460

[4] N. Carolina, Short-Circuit Capability of 1200V SiC MOSFET and JFET for Fault Protection, Appl. Power Electron. Conf. Expo. (APEC), 2013, pp.197-200.

DOI: 10.1109/apec.2013.6520207

[5] S. Niu, et al., Bulk thickness and short circuit capacity of a 1200V 4H-SiC VJFET, Materials Science Forum, 2015, vols. 821-823, p.797–800, (2015).

DOI: 10.4028/www.scientific.net/msf.821-823.797

[6] J. Zhao, Power junction field effect power transistor with highly vertical channel and uniform channel opening, Google Patents, (2007).

[7] A. Ritenour, et al., Saturation current improvement in 1200 V normally-off SiC VJFETs using non-uniform channel doping, Power Semiconductor Devices & IC's (ISPSD), 2010, p.361–364.