Viable 3C-SiC-on-Si MOSFET design disrupting current Material Technology Limitations

The cubic polytype (3C-) of Silicon Carbide (SiC) is an emerging semiconductor technology for power devices. The featured isotropic material properties along with the Wide Band Gap (WBG) characteristics make it an excellent choice for power Metal Oxide Semiconductor Field Effect Transistors (MOSFETs). Nonetheless, material related limitations originate from the advantageous fact that 3C-SiC can be grown on Silicon (Si) wafers. One of these major limitations is an almost negligible activation of the p-type dopants after ion implantation because the annealing has to take place at relatively low temperatures. In this paper, a novel process flow for a vertical 3C-SiC-on-Si MOSFET is presented to overcome the difficulties that currently exist in obtaining a p-body region through implantation. The proposed design has been accurately simulated with Technology Computer Aided Design (TCAD) process and device software and a comparison is performed with the conventional SiC MOSFET design. The simulated output characteristics demonstrated a reduced on-resistance and at the same time it is shown that the blocking capability can be maintained to the same level. The promising performance of the novel design discussed in this paper is potentially the solution needed and a huge step towards the realisation of 3C-SiC-on-Si MOSFETs with commercially grated characteristics

On the suitability of 3C- Silicon Carbide as an alternative to 4H- Silicon Carbide for power diodes

Major recent developments in growth expertise related to the cubic polytype of Silicon Carbide, the 3C-SiC, coupled with its remarkable physical properties and the low fabrication cost, suggest that within the next years, 3C-SiC devices can become a commercial reality. Inevitably, a comparison to the most well developed polytype of SiC, the 4H-SiC, should exist. It is therefore important to develop Finite Element Method (FEM) techniques and models for accurate device design, analysis and comparison. It is also needed to perform an exhaustive investigation with scope to identify which family of devices, which voltage class and for which applications this polytype is best suited. In this work, we validate the recently developed Technology Computer Aided Design (TCAD) material models for 3C-SiC and those of 4H-SiC with measurements on power diodes. An excellent agreement between measurements and TCAD simulations was obtained. Thereafter, based on this validation, 3C- and 4H-SiC vertical power diodes are assessed, to create trade-off maps. Depending on the operation requirements imposed by the application, the developed trade-off maps set the boundary of the realm for those two polytypes and allows to predict which applications would benefit once electrically graded 3C-SiC becomes available