Study of leakage current and breakdown issues in 4H–SiC unterminated Schottky diodes

• Published in: Solid-state electronics Vol. 53; no. 1; pp. 14 - 17
• Main Authors: Muzykov, P.G., Bolotnikov, A.V., Sudarshan, T.S.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 2009; Elsevier
• Subjects: Applied sciences; Breakdown; Diodes; Electric potential; Electronics; Exact sciences and technology; Leakage current; Schottky diode; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Silicon carbide; Surface treatment; Voltage; 85.30.De; 85.30.Hi; 73.25.+i; 52.80.−s; Silicon carbide; 73.40.Ns; Breakdown; Leakage current; Schottky diode; High strength current; Electric breakdown; Surface current; 52.80.-s; Surface treatment; Breakdown voltage; Abrupt junction; Schottky barrier diode; Damaging; Passivation
• ISSN: 0038-1101; 1879-2405
• DOI: 10.1016/j.sse.2008.09.014

In this work, electrical breakdown and the origin of reverse leakage current in 4H–SiC/Ni Schottky barrier diodes without edge termination and passivation were studied. Experimental results indicate that the SiC surface surrounding the metal contact and triple-junction region, rather than crystallographic defects in the epitaxial layer, were responsible for high leakage current and premature breakdown of the as-fabricated diodes. A post-fabrication surface treatment was implemented to investigate the surface contribution to leakage current and breakdown voltage. The diodes exposed to surface treatment exhibit breakdown voltage of about 1000 V or more, which is about two times higher than that of as-fabricated diodes and about 25% of the breakdown voltage for the parallel plane abrupt junction based on the epilayer blocking capability. Experimental data describing the breakdown-related behavior of the SBDs along with surface-controlled leakage current and breakdown are given, which can be useful for researchers developing SBDs. Issues related to practical applications are also addressed.