Paper PS2-TuA11
Pattern Loading in Etch through Profile Simulation

Tuesday, October 20, 2015, 5:40 pm, Room 210B

Pattern transfer in microelectronics fabrication extensively uses plasma-assisted etching processes. Optimization of etch processes for 3D structures, such as FinFETs and Tri-Gate transistors, utilized in current technology nodes is considerably more difficult. For example, etching of 3D structures and mask layouts typically require longer over-etch process time to clear material, especially in corners, introducing additional selectivity challenges to maintain feature scale critical dimensions (CDs). In addition, feature open area, feature orientation, and proximity to other nearby structures can influence process etch outcomes. While for past technology nodes, 2D etch profile models were sufficient to optimize features and connect reactor scale properties to feature evolution, 3D structures are not well represented by 2D profile simulations.

In this paper, we report on the recent development and progress of a 3D profile simulator: the Monte Carlo Feature Profile Model (MCFPM-3D). The modeling platform in MCFPM-3D includes many advanced features such as charging, mixing, implantation, and photon-stimulated processes. The model addresses reaction mechanisms resulting in etching, sputtering, mixing, and deposition on the surface to predict profile evolution based on fluxes of radicals, ions, and photons provided by an equipment scale simulator. In these studies, energy and angularly resolved fluxes are provided by the Hybrid Plasma Equipment Model (HPEM). Results from profile simulations of feature pattern loading in etching of 2D and 3D structures will be presented. Phenomena such as reactive ion etch lag and aspect ratio dependent etching will be discussed.