PETEOS simulation using EVOLVE, a deposition simulator

Abstract

In this paper, we compare simulated and experimental silicon dioxide film profiles deposited over metal lines on a silicon substrate using plasma enhanced deposition from a mixture of tetraethoxysilane (TEOS) and oxygen. The deposition was performed in an Applied Materials Precision CVD 5000 at 673 K, 9 Torr, a 9:5 TEOS to oxygen feed flow rate ratio, and a power density of 10 W cm −2. We use EVOLVE, a physically based low pressure deposition simulator, to simulate this deposition using the structure of a set of constitutive relationships developed for this deposition process at very different deposition conditions. These constitutive models include (1) a plasma model, (2) a plasma sheath model and (3) the kinetics of the deposition reactions. By adjusting two independent parameters of the constitutive models, good agreement between simulated and experimental profiles is found. We also discuss a few common obstacles encountered while trying to match the details of simulated and deposited film profiles. We do not consider the simulations discussed in this paper to be completely physically based, because the constitutive relationships required for completely physically based simulations are not available. Regardless, process development can be guided by the results obtained through these simulations. In addition, comparisons between simulated and experimental profiles can provide information with which to design experiments to improve the constitutive relationships for a given deposition process.