Remote plasma atomic layer deposited Al<inf>2</inf>O<inf>3</inf> 4H SiC MOS capacitor with remote H<inf>2</inf> plasma passivation and post metallization annealing

Hydrogen (H<inf>2</inf>) plasma treatment at the interface between 4H-SiC substrate and Al<inf>2</inf>O<inf>3</inf> dielectric prepared by the atomic layer deposition (ALD) was performed and its effects on capacitance-voltage characteristics as well as the interface state density (D<inf>it</inf>) was evaluated with metal oxide semiconductor devices. The atomic force microscopy result indicates that the remote H<inf>2</inf> plasma treatment reduces surface roughness. Compared with the non-passivated devices, lower leakage current, lower hysteresis and higher breakdown voltage are attained with remotely hydrogen plasma-treated devices. Without post metallization annealing (PMA), D<inf>it</inf> value more than 10¹⁴ eV^-1 cm^-2 is attained with hydrogen plasma passivated devices, indicating plasma-induced damage on the surface. However, using PMA, D<inf>it</inf> of the H<inf>2</inf> plasma treated device is significantly reduced to as low as 1.00 × 10¹² eV^-1 cm^-2 at E<inf>c</inf> - E<inf>t</inf> = 0.4 eV and is about five times lower than that of sample without H<inf>2</inf> plasma passivation (D<inf>it</inf> = 4.84 × 10¹² eV^-1 cm^-2).