3D TCAD Simulations for More Efficient SiC Power Devices Design

Abstract

SiC devices become more and more prominent in the power semiconductor industry. Thanks to a technology that seems to be mature enough, SiC devices become more and more sophisticated. Therefore, they can be serious competitors to existing silicon devices in not so distant future at least for high temperature and high power applications. In addition to undoubtedly better electrical and thermal properties, SiC devices still require attention regarding their design. Indeed, the material is still more expensive than silicon and some limitations such as the inability to create deep p-n junctions prevent from re-using existing silicon design. Therefore, SiC devices should be designed so that the best trade-off between active area and breakdown voltage is achieved. In such a context, 3D TCAD can be become an interesting approach mostly thanks to modern computer farms.

10 kV Silicon Carbide PiN Diodes—From Design to Packaged Component Characterization

“…In order to sustain the high voltage, the junction termination has to be designed to spread the electric field that naturally occurs at the edge of the termination. A plethora of papers present in the literature report on techniques that fulfill this task with a relatively high efficiency (>80%) [16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35]. Another study on high-voltage bipolar diodes from SuperGrid has shown that an efficient peripheral protection is achieved by a mesa structure with a combination of junction termination extension (JTE) with JTE rings.…”

“…A smaller JTE length would result in a very small radius of curvature and produces a field crouding at the edges of the rectangular devices. Two-dimensional simulations do not take into account the radius of curvature and give a wrong impression on the JTE efficiency [28,36]. The next step is to compute the number of useful JTE rings.…”

“…Since the higher number of rings increases the dose tolerance, six rings were chosen with optimized width and increasing distance between them. Three-dimensional simulations could have been carried out to show the necessity of 400 µm JTE and six rings, but would require a long computing time [28].…”