Modeling Deformation Due To Surface Oxidation In Integrated Circuits

摘要

Oxidation of high aspect ratio IC structures, such as pillars and fins, can deform them. Disclosed is technology for simulating the deformation efficiently so that process conditions or pattern design can be altered to improve manufacturability. A database describing a 3D model of the structures prior to the oxidation process is provided. Oxidation is simulated in 1D on different surfaces to estimate a depth of starting material that will be converted during oxidation. Starting material is then replaced to that depth on all surfaces, by oxide with known expansion ratio. An initial mechanical stress and strain field is determined based on the model in dependence upon the replacement depth and the expansion ratio, and the system relaxes the fields to their equilibrium states, which include the deformations. The deformations are reported to a user, who can repeat the process using different oxidizing conditions and/or patterns to optimize manufacturability.