Modeling of Si self-diffusion in SiO2: Effect of the Si/SiO2 interface including time-dependent diffusivity

• Published in: Applied physics letters 2004-02, Vol.84 (6), p.876-878
• Main Authors: Uematsu, Masashi, Kageshima, Hiroyuki, Takahashi, Yasuo, Fukatsu, Shigeto, Itoh, Kohei M., Shiraishi, Kenji, Gösele, Ulrich
• Format: Article
• Language: English
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.1644623

Self-diffusion of Si in thermally grown SiO2 is modeled taking into account the effect of SiO molecules generated at the Si/SiO2 interface and diffusing into SiO2 to enhance the self-diffusion. Based on the model, a recent self-diffusion experiment of ion-implanted Si30 in SiO2, which showed increasing self-diffusivity with decreasing distance between the Si30 diffusers and Si/SiO2 interface [Fukatsu et al., Appl. Phys. Lett. 83, 3897 (2003)], was simulated, and the simulated results fit the experimental profiles. Furthermore, the simulation predicts that the self-diffusivity would increase for a longer annealing time because more SiO molecules should be arriving from the interface. Such time-dependent diffusivity was indeed found in our follow-up experiments, and the profiles were also fitted by the simulation using a single set of parameters.