Influence of an In-Situ Formed Interfacial SiNx Layer on the Electrical Performance and Thermal Stability of High-k HfO2 Films

Abstract

The influence of an in-situ formed SiNx layer at the interface between a Si substrate and atomic-layer-deposited high-k HfO2 film on the structural stability and electrical performance was investigated. It was found that the densely formed SiNx layer strongly reduces the degradation in capacitance density and interface trap properties during post-deposition annealing up to 1000oC. This is mostly due to a reduced SiO2 formation at the HfO2/SiNx interface during post-annealing. Hf-silicate is mostly formed on the surface region of the film during post- annealing which is also reduced by the SiNx layer.

Improved interface properties of an HfO2gate dielectric GaAs MOS device by using SiNxas an interfacial passivation layer

“…4(b), it can be noted that the peak corresponding to the Ga-O bond is not observed, indicating that Ga oxides have been suppressed by 600 • C PDA. The weaker-intensity peaks of the native oxides for the SiN x 600 sample also mean that the PDA at 600 • C can more effectively prevent out-diffusion of Ga and As than at 500 • C, because a densified and high-quality SiN x IL can be formed during PDA at 600 • C. [22] These results indicate that the SiNx IL annealed at higher temperature (e.g., 600 • C) can effectively suppress the growth of the native oxides compared with that at lower temperature (e.g., 500 • C). This is why the SiN x 600 sample has better quality of interface and electrical properties than the SiN x 500 sample.…”