Abstract: In a method of depositing a transparent electrically conductive metal oxide coating by reactive sputtering onto the surface of a substrate, the substrate is supported, in spaced relationship with a cathode which is to be sputtered, in a vacuum chamber containing an atmosphere comprising an inert gas and a controlled oxygen concentration at a selected total pressure. The substrate is heated prior to sputtering to a selected elevated temperature, and reactive sputtering is caused by applying a selected negative potential relative to the substrate. The oxygen in the atmosphere is provided and maintained at a selected concentration, and the heating of said substrate is controlled during sputtering to maintain the substrate temperature substantially constant at the selected temperature during substrate heating caused by sputtering.

Abstract: A substantially uniform, transparent, electrically conducting, metal oxide film (e.g. of indium/tin oxide) can be deposited on to a substrate such as glass of large lateral dimensions, e.g. a windscreen for an aircraft or a land vehicle, by low-pressure reactive sputtering from a cathode of the metal, using an atmosphere of oxygen and another gas or gases (preferably an inert gas) at reduced pressure, by providing access for the sputtering atmosphere to penetrate into the whole of the working space between the cathode and the substrate so as to maintain a substantial degree of uniformity in the oxygen concentration in the working space. Access for the atmosphere may be provided by means of passages extending through the cathode assembly, by dividing the cathode assembly into parallel strips separated by gaps, and the atmosphere may be supplied direct to the working space through such gaps. Relative movement is effected between the cathode assembly and the substrate, e.g.