A plasma source , comprising: - an outer face , comprising at least one aperture for delivering a plasma from the aperture; - a transport mechanism configured to transport a substrate and the plasma source relative to each other along the outer face; - a counter electrode comprising at least first (3-1) and second faces (3-3) that extend in a direction away from the substrate; - a working electrode , comprising multiple planar shaped tiles (4-1, 4-2, 4-3), in which a tile comprises at least one film shaped conductive layer (2-1, 2-2 2-3) that is at least in part enclosed by a dielectric layer (1-1, 1-2, 1-3); - at least two plasma collection spaces in communication with the at least one aperture, wherein a first plasma collection space (6-1) is formed at least in part between a first face of the counter electrode and a first face of the working electrode, and a second plasma collection space (6-3) is at least in part formed between a second face of the counter electrode and a second face of the working electrode; - a gas inlet to provide gas flow to the aperture through the at least two plasma collection spaces; - wherein a first (4-1) and second tile (4-2) are arranged within a first plane of the working electrode with neighbouring edges bordering said first plasma collection space and a third tile (4-3) is arranged in a second plane of the working electrode parallel to the first plane such that the third tile overlaps said neighbouring edges in the first plane; and - wherein at least one of the working and counter electrodes comprises a local modification near said neighbouring edges to increase a plasma delivery to the aperture compensating for loss of plasma collection due to the neighbouring edges. - an outer face , comprising at least one aperture for delivering a plasma from the aperture; - a transport mechanism configured to transport a substrate and the plasma source relative to each other along the outer face; - a counter electrode comprising at least first (3-1) and second faces (3-3) that extend in a direction away from the substrate; - a working electrode , comprising multiple planar shaped tiles (4-1, 4-2, 4-3), in which a tile comprises at least one film shaped conductive layer (2-1, 2-2 2-3) that is at least in part enclosed by a dielectric layer (1-1, 1-2, 1-3); - at least two plasma collection spaces in communication with the at least one aperture, wherein a first plasma collection space (6-1) is formed at least in part between a first face of the counter electrode and a first face of the working electrode, and a second plasma collection space (6-3) is at least in part formed between a second face of the counter electrode and a second face of the working electrode; - a gas inlet to provide gas flow to the aperture through the at least two plasma collection spaces; - wherein a first (4-1) and second tile (4-2) are arranged within a first plane of the working electrode with neighbouring edges bordering said first plasma collection space and a third tile (4-3) is arranged in a second plane of the working electrode parallel to the first plane such that the third tile overlaps said neighbouring edges in the first plane; and - wherein at least one of the working and counter electrodes comprises a local modification near said neighbouring edges to increase a plasma delivery to the aperture compensating for loss of plasma collection due to the neighbouring edges. <EOS>