Physical Models for SiC and Their Application to Device Simulations of SiC Insulated-Gate Bipolar Transistors

Important physical models for 4H silicon carbide (4H-SiC) are constructed based on the literature and experiments on the physical properties of 4H-SiC. The obtained physical models are implemented into a commercial device simulator, which is used for examining the potential performance of SiC insulated-gate bipolar transistors (IGBTs). Device simulation using these new physical models shows that the forward characteristics of the conventional type of planar SiC IGBTs are significantly poorer than those of SiC p-i-n diodes, even if the carrier lifetime is improved. It is shown that the degradation in the characteristics of the conventional SiC IGBT is caused by the limited conduction modulation at the cathode side of the n-base layer. We show that this problem can be resolved by applying device structures that induce a hole-barrier effect in the SiC IGBTs.