Formation of High-Quality SiO2 and SiO2/Si Interface by Thermal-Plasma-Jet-Induced Millisecond Annealing and Postmetallization Annealing

For the formation of a high-quality SiO 2 and SiO 2 /Si interface, we have applied thermal-plasma-jet (TPJ)-induced millisecond annealing to SiO 2 films deposited at 300 °C by plasma-enhanced chemical vapor deposition (PECVD). By TPJ annealing at 1088 K for 2.8 ms, the amount of Si–OH bond groups decreased significantly and an increase in the amount of Si–O–Si bond groups was observed. This result suggests that the desorption of H 2 O and the cross linkage of Si–O–Si are promoted, and the densification of SiO 2 films is achieved. By performing TPJ annealing followed by postmetallization annealing (PMA), a high-quality SiO 2 /Si interface with a trap density ( D it ) of 3.0×10 10 cm -2 eV -1 was achieved. In addition, TPJ-annealed SiO 2 films show a higher durability under a constant current stress than SiO 2 films prepared only by PMA. This is attributed to the improvement of the bulk chemical bond network of SiO 2 films by TPJ annealing. These results indicate that the combination of TPJ and PMA is one of the promising low-temperature processes for the long-term reliability of SiO 2 films and the formation of a high-quality SiO 2 and SiO 2 /Si interface.