Modeling and Control of SiNx Film Growth using the Kinetic Monte Carlo Method: Impact of Gas Flow Rate on Surface Roughness and Film Thickness

A systematic methodology is developed for modeling and controlling the surface roughness in LPCVD SiNx film deposition. The deposition process is modeled via kinetic Monte Carlo (KMC) simulation on a three-dimensional triangular lattice using disilane (Si2H6) and ammonia (NH3) as precursor sources. New algorithmic modifications are considered in our simulations to create a SiN compound with small Si clusters and a rough surface. The nanoscopic events included in this study are particle adsorption and subsequent migration, leading to the development of vacancies and pores. Vacancies and pores are allowed inside the porous SiNx film to model film thickness and surface roughness. The roughness and thickness of the obtained nanostructures are calculated in terms of the gas flow ratio, and a new method is proposed. Simulation results illustrate the effectiveness of the proposed modeling and control approach in the context of the surface roughness under consideration. Since the simultaneous control of surface roughness and film thickness is carried out, the obtained surface height structures are regulated to desired values. The formation of peaks and valleys is defined in our KMC algorithm. The dependence of surface roughness and film thickness on silicon (Si) cluster size is studied. The simulations reveal the existence of a minimum surface roughness after increasing the gas flow ratio.