Coating module with improved cathode arrangement

A coating module for a coating system, wherein the coating module comprises a process chamber which can be evacuated, a chamber lid for closing the process chamber in a vacuum-tight manner, and a coating unit consisting of a coating target, a target backplate, a dark space shield, and a magnet system, wherein the coating target, the target backplate and the dark space shield are mounted in the process chamber, wherein the magnet system is mounted on the chamber lid, wherein the coating target, the target backplate and the dark space shield are not connected to the chamber lid so that lifting the chamber lid from the process chamber separates the magnet system from the rest of the coating unit, wherein an inner side of the chamber lid comprises a concave curvature, wherein the concave curvature is designed in relation to a thickness of the chamber lid and a vacuum provided during operation in such a way that the inner side of the chamber lid is configured in a flat manner under vacuum.