Simulation of pattern effect induced by millisecond annealing used in advanced metal-oxide-semiconductor technologies

The submelt millisecond annealing process was introduced in the context of complementary metal-oxide semiconductor technology downscaling to enhance the activation of dopants. However, circuit designs can produce nonuniform local radiative and thermal dispersion properties at the front side of a wafer. Nonuniformities lead to local variations in annealing temperature and, therefore, to variability in device electrical properties and performance. This so-called pattern effect, well known in the context of lamp-based rapid thermal processing systems, is investigated here by simulation of the annealing process on the millisecond time scale. The multiphysics simulation models both optical and thermal properties. Real design inputs were imported from layout files and a finite element method simulation was used to compute transient temperature fields during the process. The absorptivities of a variety of periodic patterned structures were investigated by optical modeling. The radiative and thermal properties of the devices were mapped at the circuit scale. Finally, a three-dimensional thermal simulation was performed to evaluate the intradie thermal dispersions, which were found to be as large as 45°C in the real system.