Antisite Defect Si_C as a Source of the D_I Center in 4H‐SiC

Abstract

DI center, as a widely existed defect in 4H‐SiC, has attracted much attention in recent years, while the origin of it is still unclear. Herein, by comparing first‐principles calculated potential point defects‐related zero‐phonon lines (ZPLs) and nonradiative capture cross‐sections with the DI center‐related values in the experiment, it is proposed that the transition from the bound exciton states about 57 meV below the CBM to the “+1/+2” level of antisite defect SiC is responsible for the DI center in 4H‐SiC. This work describes the temperature and transition energy level dependence of the hole capture cross‐section of antisite defect in 4H‐SiC, which provides an idea for the optimal design of point defects in semiconductor materials.

IBIL Measurement and Optical Simulation of the DI Center in 4H-SiC

“…To take into account the systematic error of the calculation, the results are regarded as reasonable. We notice the defect Si C from q = 1 to q = 2 was proposed as the composite of D I defect [ 34 ], but we also notice there are some debates on the structure. The recombination of carbon vacancy(V C ) and Si interstitial (Si i ) above 1200 °C is suggested to create Si C defect [ 35 ].…”

Imperfections are not 0 K: free energy of point defects in crystals

“…We note that, due to the symmetry lowering induced by the defect formation, evaluating A vib d is often significantly more computationally demanding than A vib b . For large supercells, the calculation of A vib d can be simplified by applying the Combined Dynamic Matrix approximation, [101][102][103][104][105][106][107][108] which only calculates the interatomic force constants for the interactions affected by the defect formation. In practice, a cut-off radius R c E 3.2-4 Å is defined around the defect centre, and the interatomic force constants F i,j are only calculated if at least one of the atoms i or j is located within the cut-off distance R c .…”

Electrical Conductivity Improvement of Point Defects in 4H-SiC

“…In this study, atomic models of point defects in 4H-SiC are constructed and analyzed with regard to their properties, such as Hall mobility, electrical conductivity, and molecular dynamic stability. Point defects in 4H-SiC include vacancy and interstitial defects, and the properties could be predicted by density functional theory (DFT) − calculations. Suppose a defect is difficult to remove and potentially hinders the development of high and low electrical conductivity 4H-SiC substrates.…”