Comparison of aluminum- and boron-implanted vertical 6H-SiC p+n junction diodes

Autor: T.P. Chow, Mario Ghezzo, D.M. Brown, Vishnu K. Khemka, Philip G. Neudeck, R. Tyagi, William Andrew Hennessy, N. Ramungul, James W. Kretchmer
Rok vydání: 1998
Předmět:
Zdroj: Solid-State Electronics. 42:17-22
ISSN: 0038-1101
DOI: 10.1016/s0038-1101(97)00217-7
Popis: The electrical performance of mesa type 6H-SiC p + n junction diodes formed via high temperature implantation of 27 Al and 11 B has been comparatively studied and analyzed at temperatures up to 400°C using the Shockley model and the space-charge-limited current model. The Al-implanted diodes show better forward current–voltage characteristics with the best ideality factor obtained at 400°C of 1.6 while that for B-implanted diodes is 1.3. The factor that prohibits the forward performance of the Al-implanted diodes appears to be the deep defect center located at 1.2 eV above the valence band while that of B-implanted diodes appears to be the deep boron center called D-center located at 0.7∼0.8 eV above the valence band. On the other hand, B-implanted diodes show a better yield in the reverse direction with at least an order-of-magnitude lower reverse leakage current than that of Al-implanted diodes at all measurement temperatures. Several micropipe microplasmas were plainly visible in the middle of the mesa of the Al-implanted diodes when biased at −250 V but not on boron devices. The forward voltage drop of Al-implanted diodes is tightly distributed at 2.2 V with a forward resistance of 125 Ω while that of B-implanted diodes is broadly distributed with an average value of 2.8 V and nearly 200 times larger forward resistance.
Databáze: OpenAIRE
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