A Study on Computational Fluid Dynamic Simulations to Improve the Thickness Uniformity of Porous Metal Films Deposited by Using Cluster Sputtering

Abstract

We conducted computational fluid dynamic (CFD) simulations to improve the thickness uniformity of cluster-sputtered porous metal films. The cluster sputtering equipment was divided into a module where the sputtered metal atoms condensed and cluster nanoparticles formed and a chamber where porous metal films were deposited. To optimize the equipment geometry, we performed simulations and deposition experiments for various planar nozzle positions and nozzle-to-substrate distances in the module. The simulated gas velocity distribution 25 mm above the substrate exhibited a similar tendency to the thickness distribution of the deposited porous Cu films. When a 4-mm nozzle was located 40 and 240 mm from the module center and substrate, respectively, the simulated gas velocity distribution exhibited uniformity to within 8.4% for the substrate with a 70-mm radius. The thickness uniformity and the deposition rate of the deposited porous Cu films were 9.3% and 2 µm/min, respectively, using equipment with the same geometry.