Physical parameterisation of 3C-Silicon Carbide (SiC) with scope to evaluate the suitability of the material for power diodes as an alternative to 4H-SiC

Abstract

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 five years, 3C-SiC devices can become a commercial reality. It is therefore important to develop Finite Element Method (FEM) techniques and models for accurate device simulation. Furthermore, it is also needed to perform an exhaustive simulation investigation with scope to identify which family of devices, which voltage class and for which applications this polytype is suited. In this paper, we present a complete set of physical models alongside with our developed set of material parameters for bulk 3C-SiC aiming Technology Computer Aided Design (TCAD) tools. These are compared with that of 4H-SiC, the most well developed polytype of SiC. Thereafter, the newly developed material parameters are used to assess 3C-and 4H-SiC vertical power diodes, PIN and Schottky Barrier Diodes (SBDs), to create trade-off maps relating the on-state voltage drop and the blocking capability. Depending on the operation requirements imposed by the application, the developed trade-off maps set the boundary of the realm for those two polytypes which allows us to predict which applications will benefit from an electrically graded 3C-SiC power diodes.

On the Suitability of 3C-Silicon Carbide as an Alternative to 4H-Silicon Carbide for Power Diodes

“…The authors of this paper developed for the first time a comprehensive set of physical models and their assorted material parameters for the 3C-SiC which is explicitly discussed in [30]. Thereafter, the authors proceed with a thorough validation process, which led to a modified set of coefficient values enabling a wider range of level of accuracy with doping and temperature [31].…”

“…In high electric field conditions, the Canali model (2) [39] utilizes the C-T calculated mobility for low fields and the saturation velocity property of the carriers in SiC as listed in Table I For the reverse bias simulations, the impact ionization is modelled for 3C-SiC utilizing the van Overstraeten-de Man formula (3) [40]. In [30], the values of avalanche ionization coefficients were different to those used in this work for 3C-SiC. In [30] the coefficients for electrons were assumed to be the same with those of holes.…”

“…In [30], the values of avalanche ionization coefficients were different to those used in this work for 3C-SiC. In [30] the coefficients for electrons were assumed to be the same with those of holes. The reason behind the aforementioned decision was the lack of information regarding the coefficients of electrons.…”

“…Further, due to the aforementioned reasons the physical models of 3C-SiC are underdeveloped. Recent advancements in this field include the development of a comprehensive set of 3C-SiC models [30] [31] and the simulation of power devices [32]- [35]. However, to the best of the authors' knowledge, no reports on the validation of those models with the use of measurements of 3C-SiC power structures exist, a necessary step to ensure the valid use of FEM for the design of 3C-SiC devices.…”

TCAD Device Modelling and Simulation of Wide Bandgap Power Semiconductors

“…The corresponding values required in a physics parameter file for 4H-SiC were developed and improved alongside the improvement of the technology. Recently there have been efforts to compile an equivalent set of parameters for 3C and to validate them [12,13]. This section presents the required models and the parameters of both materials.…”