Abstract
Abstract Ti/SiO2/Si, TiN/Si and TiN/Ti/SiO2/Si structures were annealed in vacuum to observe the ability of Ti absorbing oxygen and the stress relaxation of TiN layer. The stress of the film was determined in situ by measuring the curvature of the sample during the annealing process. The phases and the microstructure of the film after annealing process were identified using XRD, AES, and TEM. A clear correlation was between the evolution of stress and the absorption of oxygen atoms by the Ti film. From the XRD data, we can find that the (002) peak of Ti shifts to low angle at 280oC~400oC in the Ti/SiO2/Si system. It is due to the oxygen-induced Ti lattice expansion. The content of oxygen increases as the annealing temperatures and time increase, and this process let the stress become more compressive. The experiment finds that the content of oxygen can be monitored by in-situ curvature measurement. Moreover, diffusivity and the activation energy of oxygen in Ti film can be extracted. The stress relaxation of TiN is due to grain growth proved by Dark Field TEM and XRD intensity. The starting temperatures for the stress relaxation are different between TiN/Si and TiN/Ti/SiO2 system because of different TiN textures in these two systems.