On Increasing the Accuracy of Simulations of Deposition and Etching Processes Using Radiosity and the Level Set Method

Deposition and etching in Silicon trenches is an important step of today’s semiconductor manufacturing. Understanding the surface evolution enables to predict the resulting profiles and thus to optimize process parameters. Simulations using the radiosity modeling approach and the level set method provide accurate results, but their speed has to be considered when employing advanced models and for purposes of inverse modeling. In this paper strategies for increasing the accuracy of deposition simulations while decreasing simulation times are presented. Two algorithms were devised: first, intertwining narrow banding and extending the speed function yields a fast and accurate level set algorithm. Second, an algorithm which coarsens the surface reduces the computational demands of the radiosity method. Finally measurements of a typical TEOS deposition process are compared with simulation results both with and without coarsening of the surface elements. It was found that the computational effort is significantly reduced without sacrificing the accuracy of the simulations.