Simulation of SiO2 and Si feature etching for microelectronics and microelectromechanical systems fabrication: A combined simulator coupling modules of surface etching, local flux calculation, and profile evolution

Abstract

A combined simulator linking gas flux data from a plasma reactor (experimental or simulated) to the feature profile evolution during etching/deposition processes is described. This combined simulator results from the coupling of surface etch, local flux calculation, and profile evolution modules. It is a modular tool, in the sense that different phenomena, surface models, and structures can be incorporated. In this work the combined simulator is applied in two processes: (a) in SiO2 feature etching to simulate reactive ion etching (RIE) lag and inverse RIE lag and (b) in etching of high aspect ratio Si trenches using the Bosch process. The profile evolution algorithm of the combined simulator, namely, the level set method, is applied to a process where etching and deposition occur, and tracking of two materials (Si and polymer formed during the Bosch deposition step) is needed.