1. Proton radiation effects in 4H-SiC diodes and MOS capacitors
- Author
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Luo, Zhiyun, Chen, Tianbing, Ahyi, Ayayi C. Sutton, Akil K., Haugerud, Becca M., Cressler, John D., Sheridan, David C., Williams, John R., Marshall, Paul W., and Reed, Robert A.
- Subjects
Diodes -- Research ,Metal oxide semiconductors -- Research ,Business ,Electronics ,Electronics and electrical industries - Abstract
Proton irradiation is used to probe the physics of 4H-silicon carbide (SIC) Schottky barrier diodes (SBDs) and negative channel metal oxide semiconductor (nMOS) capacitors for the first time. Both 4H-SiC SBD diodes and SiC MOS structures show excellent radiation tolerance under high-energy, high-dose proton exposure. Unlike for SiC JBS diodes, which show a strong increase in series resistance after proton irradiation, these SiC SBDs show very little forward bias I-V degradation after exposure to 63.3 MeV protons up to a fluence of 5 x [10.sup.13] p/[cm.sup.2]. An improvement in reverse leakage current after irradiation is also observed, which could be due to a proton annealing effect. The small but observable increase in blocking voltage for these SiC SBDs is attributed to a negative surface charge increase, consistent with earlier gamma results. The resultant [Q.sub.eff] change of 4H-SiC nMOS capacitors under proton irradiation was used to quantify the radiation induced changes to the blocking voltage in the SBD diodes in MEDICI simulations, and showed a good agreement with the experimental data. Characterization of these capacitors also suggests that 4H-SiC MOS structures are radiation hard. Index Terms--Negative channel metal oxide semiconductor (nMOS) capacitors, Schottky barrier diodes (SBDs).
- Published
- 2004