A novel design approach for the epitaxial layer for 4H-SiC and 6H-SiC power bipolar devices

摘要

The paper evaluates the optimal design of the low-doped base region inside power diodes and other bipolar devices. It is demonstrated theoretically that a low-doped base region of P+N-N+ diodes can provide a high breakdown voltage and an optimal on-resistance R-on. A simple, accurate and CPU timesaving approach is presented to extract an optimal value for the base region width, W-B. and its doping concentration, N-D. The paper details an analytical relation between W-B and N-D, and gives a method for quantifying the trade-off between their values for a given breakdown voltage and for obtaining the minimal on-resistance. Analytical results are confronted with experimental results for 4H-SiC- and 6H-SiC-based diodes. (c) 2006 Elsevier Ltd. All rights reserved.