INFLUENCE OF AN IN-SITU FORMED INTERFACIAL SINK LAYER ON THE ELECTRICAL PERFORMANCE AND THERMAL STABILITY OF HIGH-K HFO_2 FILMS

摘要

The influence of an in-situ formed SiN_x layer at the interface between a Si substrate and atomic-layer-deposited high-k HfO_2 film on the structural stability and electrical performance was investigated. It was found that the densely formed SiN_x layer strongly reduces the degradation in capacitance density and interface trap properties during post-deposition annealing up to 1000°C. This is mostly due to a reduced SiO_2 formation at the HfO_2/SiN_x 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 SiN_x layer.