3D simulation of profile evolution in silicon DRIE

This paper presents a new 3D simulator, an extended version of our previous developed 2D simulator, with the capability of simulating etching and deposition in three dimensions under complex mask pattern configuration. Using this simulator and a virtual sidewall protection assumption, etching polymerization alternation process in silicon deep reactive ion etching (DRIE) has been simulated. The simulation result verifies that polymerization can reduce the undercut effect, enhance the anisotropy, and therefore, is a critical step in silicon DRIE process. Appling graphics symmetry, a narrow band method is developed and simulations of the etching of long trenches are executed efficiently. Lag effect, an important phenomenon in silicon DRIE, can be observed. At last, the simulation result is compared to experimental result and well match can be found.