Combined N2O and phosphorus passivations for the 4H-SiC/SiO2 interface with oxide grown at 1400°C

Phosphorus (P) passivation is more effective than N
₂
O passivation in improving the 4H-SiC/ SiO
₂
interface by reducing the number of traps at the 4H-SiC/SiO
₂
interface. This paper investigated the effect of combined N
₂
O and phosphorus POA on the 4H-SiC/SiO
₂
interface with oxides grown at 1400oC and used in the fabrication of MOS capacitors and FETs. These fabricated devices are also compared with the ones which have been N
₂
O and P passivations only. Results demonstrated that the phosphorus passivation technique provides the highest peak field-effect mobility for 4H-SiC MOSFETs (60 cm
²
/V.s), which is about 5 times higher than the value obtained for devices with N
₂
O annealing. The combined N
₂
O and phosphorus passivation technique, however, has shown a slight decrease in the peak field effect mobility value compared to the phosphorus passivation technique, but it is still much higher than the N
₂
O passivation technique (12 cm
²
/V.s).