Dielectric properties of rf sputtered Ta2O5on rapid thermally nitrided Si

Dielectric properties, including leakage currents of stacked structures composed of rf sputtered Ta 2 O 5 and ultrathin SiO x N y grown by rapid thermal nitridation (RTN) in N 2 O or NH 3 ambient, have been investigated. It was previously established that the leakage current in the structures is controlled by both hopping conduction and tunnelling in the SiO x N y layer and Poole-Frenkel emission in Ta 2 O 5 . The analysis shows that the RTN in N 2 O gives higher barriers, lower SiO x N y layer thickness and lower permittivity than in NH 3 . It is concluded that RTN of the Si surface before deposition of Ta 2 O 5 is a beneficial method for remarkable improvement of the parameters of the Ta 2 O 5 /Si system in terms of the permittivity and the leakage currents.