3-dimensional simulation of thermal diffusion and oxidation processes

Within the frame of the european PROMPT project in which a multidimensional process simulation system has been developed, a new 3D process simulation program (DIFOX3D) is implemented to simulate the diffusion and oxidation steps. Its integration into the PROMPT system allows to achieve full 3D process simulations of typical 3D problems arising in advanced ULSI devices (e.g. shape of isolation corners in oxidation step). Diffusion/oxidation models and numerical issues are described in this paper with emphasis on the local remeshing strategy which is a key point to solve the oxidation problem. The benefits of these new simulation capabilities are demonstrated by the study of 3D effects in LOCOS structure.