Numerical Simulation of an Entire Wafer Surface during Ozone-Based Wet Chemical Etching

• DOI: 10.1021/acs.iecr.0c03382
• Publication Date: 2020-09-16T18:00:47Z
• Authors: Lena Mohr; Tobias Dannenberg; Anamaria Moldovan; Martin Zimmer; Claas Müller
• Keywords: Isotropic etching; Chemical Mechanical Planarization

In microelectromechanical system manufacturing and especially in the photovoltaic industry, wet-chemical baths are used for surface structuring, conditioning, cleaning. Ozone-based cleaning processes show, addition to of silicon wafers, ancillary effect intended material etch back. Previous studies observed inhomogeneities over wafer occurring during ozone-based wet chemical process. Since a detailed observation process basin is not possible, simulations carried out understand what causes these inhomogeneities. Therefore, an existing microscopic two-dimensional (2D) model reaction modelling extended stepwise from length several microns full 157 mm industrial solar cell. Subsequently, 2D transferred three-dimensional (3D) model. addition, initial water layer, originating previous rinsing step, movement handling were taken into account modeling. This approach allows estimation etching entire first time enables better understanding reasons The layer connection with fast masking, carrier rods, leads stripes on surface, shown by differences reflection. As removed homogeneously, masked areas delayed results uneven surface. removal simulation (8.51 ± 0.37 nm) accordance experimental data (9.02 1.10 nm). presented can serve as base future work estimate effects parameter changes, e.g., plant design or composition solution homogeneity back process, thus enabling cost efficient optimization.