Molecular dynamics simulation of amine formation in plasma-enhanced chemical vapor deposition with hydrocarbon and amino radicals.

This article focuses on molecular dynamics (MD) simulations investigating the formation of primary amines (−NH₂) in carbon-based polymer films deposited by plasma-enhanced chemical vapor deposition (PECVD) using methane (CH₄) and nitrogen (N₂) gases. The study models the deposition process assuming nitrogen is supplied solely as amino radicals (NH₂) to maximize primary amine content and examines how these radicals interact with the film surface under various ion energies and hydrogen supplies. Results indicate that even under idealized conditions, the primary amine concentration remains low (around 10–12% relative to nitrogen atoms) due to surface reactions transferring hydrogen atoms from NH₂ radicals to surrounding carbon atoms, limiting primary amine retention. These findings align with experimental observations and suggest that increasing NH₂ radical density or hydrogen supply in the plasma does not significantly enhance primary amine content in the deposited films.