Ni-Based Ohmic Contacts to n-Type 4H-SiC: The Formation Mechanism and Thermal Stability

Figure 18

SEM micrographs of the Au/Ni₂Si/n-SiC (a and b) and Au/Ta₃₅Si₁₅N₅₀/Ni₂Si/n-SiC (c and d) ohmic contacts: (a, c) as-deposited and after annealing in Ar at 800°C (3 min); (b, d) after aging in air at 400°C (150 h) [85–88]. The yellow squares show the SEM micrographs with higher resolution for the contacts after heat treatments.

(a) 800°C/Ar/3 min

(b) 400°C/air/150 h

(c) 800°C/Ar/3 min

(d) 400°C/air/150 h