The p-type doping efficiency of 4 H silicon carbide(4 H-SiC)is rather low due to the large ionization energies of p-type dopants.Such an issue impedes the exploration of the full advantage of 4 H-SiC for semiconductor...The p-type doping efficiency of 4 H silicon carbide(4 H-SiC)is rather low due to the large ionization energies of p-type dopants.Such an issue impedes the exploration of the full advantage of 4 H-SiC for semiconductor devices.In this study,we show that co-doping group-IVB elements effectively decreases the ionization energy of the most widely used p-type dopant,i.e.,aluminum(Al),through the defect-level repulsion between the energy levels of group-IVB elements and that of Al in 4 H-SiC.Among group-IVB elements Ti has the most prominent effectiveness.Ti decreases the ionization energy of Al by nearly 50%,leading to a value as low as~0.13 eV.As a result,the ionization rate of Al with Ti co-doping is up to~5 times larger than that without co-doping at room temperature when the doping concentration is up to 10^(18)cm^(-3).This work may encourage the experimental co-doping of group-IVB elements such as Ti and Al to significantly improve the p-type doping efficiency of 4 H-SiC.展开更多
基金Project supported by the National Key Research and Development Program of China(Grant Nos.2017YFA0205704 and 2018YFB2200101)the National Natural Science Foundation of China(Grant Nos.91964107 and 61774133)+2 种基金Fundamental Research Funds for the Central Universities,China(Grant No.2018XZZX003-02)the National Natural Science Foundation of China for Innovative Research Groups(Grant No.61721005)Zhejiang University Education Foundation Global Partnership Fund。
文摘The p-type doping efficiency of 4 H silicon carbide(4 H-SiC)is rather low due to the large ionization energies of p-type dopants.Such an issue impedes the exploration of the full advantage of 4 H-SiC for semiconductor devices.In this study,we show that co-doping group-IVB elements effectively decreases the ionization energy of the most widely used p-type dopant,i.e.,aluminum(Al),through the defect-level repulsion between the energy levels of group-IVB elements and that of Al in 4 H-SiC.Among group-IVB elements Ti has the most prominent effectiveness.Ti decreases the ionization energy of Al by nearly 50%,leading to a value as low as~0.13 eV.As a result,the ionization rate of Al with Ti co-doping is up to~5 times larger than that without co-doping at room temperature when the doping concentration is up to 10^(18)cm^(-3).This work may encourage the experimental co-doping of group-IVB elements such as Ti and Al to significantly improve the p-type doping efficiency of 4 H-SiC.
