Overview

The Rainbow® 4520i system is a single wafer, vacuum load-locked low pressure oxide system with two active processing chambers. It is designed for integrated isotropic/anisotropic profile on high aspect ratio contact and via structures. The Isotropic Module adds isotropic oxide etching capabilities to the existing anisotropic capabilities of the Rainbow 4520, providing excellent aluminum step coverage. The Isotropic Module is incorporated onto the entrance load-lock on the Rainbow 4520, requiring only one additional wafer handling step. Having two chambers on a single machine greatly reduces the possibility of cross contamination between processes, which minimizes wafer breakage and defect densities. The system has a high uptime of ≥ 85% and is capable of isotropic etching for dielectric (oxide) films. The Rainbow® 4520i system has several applications, including contact etch, planarization, via etch, trench mask etch, and pad etch.