(Digital Presentation) Investigation of Nanoconfined Wet Etching Mechanism Using MD Simulation

With the advancement in semiconductor technology, multi-dimensional geometries are being formed resulting in nanoconfined spaces. It is very difficult to etch these nanoconfined spaces uniformly across different critical dimension (CD) sizes by wet processes, where typically the etch rate (ER) decreases in narrow CDs. One of the mechanisms is the electric double layer (EDL) model, which prevents etchants from entering the nanochannels due to the overlapping of the EDL. In previous experiments, it was reported that mixing an organic solvent with an etching solution does not decrease the ER in narrow CDs. The EDL model alone cannot fully explain the mechanism in organic solvents, and other factors need to be considered. In this paper, we report the results of investigating the etching mechanism in water and organic solvents in nanoconfined spaces by calculating number density distribution and diffusion time using molecular dynamics (MD) simulations.