4H-SiC BJTs with epitaxial junction termination composite structure

摘要

The proposed novel structure can be applied to junction termination technology to fabricate 4H-SiC bipolar junction transistors (BJTs) by using epitaxial junction termination extension (JTE) to eliminate the curvature effect of the base-collector junction terminal. Furthermore, accurate p-type dopants such as floating field limiting rings (FFLRs) have been implanted in the different zones of an epitaxial JTE to achieve the different charge distribution at the terminal of the main junction and JTE to decrease the peak electric field of the surface. Compared with the conventional JTE and FFLRs, the novel device can achieve a higher breakdown voltage by 20% and 39% added without the loss of current gain. Moreover, the novel structure not only simplifies the production of conventional SiC BJTs terminal process but also avoids the lattice injury for many ion implantations to produce the complex multiple JTE and FFLRs.