Electron Transport and Dislocations in Heavily Doped and Co‐Doped n‐Type 4H‐SiC

With the increasing demand for low‐resistivity substrates, growing heavily doped 4H‐SiC crystals is emerging as a critical practice. Now, we report the growth of heavily nitrogen‐doped, nitrogen‐aluminum (N–Al) co‐doped and nitrogen‐gallium (N–Ga) co‐doped 4H‐SiC crystals by using the physical vapor transport (PVT) method. Comparative study shows that co‐doping contributes to enhanced nitrogen incorporation efficiency and leads to lower resistivity. In addition, it is found that the heavy doping shifts the Fermi level of 4H‐SiC into the conduction band. The temperature dependence of the mobility of heavily co‐doped 4H‐SiC indicates a thermally activated transport for electrons at temperatures above 300 K. Ga and Al atoms are found to effectively impede the glide and multiplication of basal plane dislocations (BPDs), reducing the density of BPDs. The N–Ga co‐doping effectively suppresses the formation of stacking faults.