Study on Simulation and Profile Prediction of Atomic Layer Deposition

Abstract

The Atomic Layer Deposition process (ALD) is widely used in FinFET, 3D-NAND and other important technologies because of its self-limiting signature and low growth temperature. In recent years, the development of computer enables chances for ALD process simulation in order to improve the process R&D efficiency. In this paper, steady state theory and vacuum pump theory are implemented to develop the growth rate algorithm of atomic layer deposition. The dynamic evolution of the deposition profile is realized based on cellular automata method, and fits the relationship between temperature and growth rate in HfO2 deposition. The model accuracy and simulation results are verified with high reliability. Based on the simulation results of this model, the influence of different substrate size and environmental dose on growth rate of pore structure is studied and analyzed. In the case of deep hole, high depth-to-width ratio hole, or when the gas entry time is below saturation, the growth rate decreases at the pore bottom. Meanwhile, the simulation considering the angle-of-inclination of the hole’s tapered sidewall indicates that the greater the angle, the better the distribution of flux.