Patent ID: 8691063

Claim:
An apparatus for depositing a coating onto a surface of a substrate comprising: a vacuum chamber with an inlet for supplying a precursor gas to the chamber, the chamber comprising, a carrier for locating the substrate in the chamber such that the substrate, when located in the carrier, constitutes a first cathode; a first anode having an aperture in which a plasma can be formed, a second cathode such that the anode is located between the first cathode and the second cathode, and a magnetic field source configured to form a substantially linear magnetic field between the first and second cathodes, the magnetic field source comprising a first magnet and a second magnet, wherein the first cathode carries the first magnet and the second cathode carries the second magnet, wherein when the substantially linear magnetic field between the first cathode and the second cathode is formed, the direction of the substantially linear magnetic field is substantially orthogonal to the surface to be coated and plasma production and deposition takes place substantially within the substantially linear magnetic field.