Method and device for plasma treatment of a flat substrate

Method and device for the plasma treatment of a substrate in a plasma device, wherein - the substrate (110) is arranged between an electrode (112) and a counter-electrode (108) having a distance d between a surface area of the substrate to be treated and the electrode, - a capacitively coupled plasma discharge is excited, forming a DC self-bias between the electrode (112) and the counter-electrode (108), - in an area of the plasma discharge between the surface area to be treated and the electrode having a quasineutral plasma bulk (114), a quantity of at least one activatable gas species, to which a surface area of the substrate to be treated is subjected, is present - it is provided that a plasma discharge is excited, - wherein the distance d has a value comparable to s = se+sg, where se denotes a thickness of a plasma boundary layer (119) in front of the electrode,; and sg denotes a thickness of a plasma boundary layer (118) in front of the substrate surface to be treated or - wherein the quasineutral plasma