Published online by Cambridge University Press: 15 February 2011
We have developed a new pre-deposition, remote N2O plasma oxidation treatment for forming nitrided SiO2 films and report here the quality and reliability of devices fabricated with these films. The Si-dielectric heterostructure process has been separated into three independently-controlled steps: i) final Si surface cleaning, and Si – SiO2 interface formation by plasma-assisted oxidation/nitridation at 300 °C; ii) remote plasma-enhanced chemical vapor deposition of nitrided dielectrics, also at 300 °C; and iii) optional post-deposition rapid thermal annealing. This paper focuses on the first step in which the oxidation has been performed with O2, N2O or N2O / O2 mixtures to control the amount of N-atoms at the interface, Nint. We show that the incorporation of up to ∼ 1015 N-atoms/cm2 at the Si-SiO2 interface by this process has no effect on threshold voltage, Vt, or peak channel transconductance, gm,max, but does improve high-field gm and transistor drive current. Improved resistance to Vt and gm,max degradation during hot-carrier stressing of sub-micron devices is also discussed.