Method for producing a solar cell

A method for producing a surface layer of a material in a pattern on a surface of a substrate having a multi level surface structure including at least one of a ridge and a recess, and sloping surface part located adjacently to a top face of said ridge and a bottom face of said recess, the method comprising:

• providing the substrate having a groove arranged in said substrate surface, said groove having a bottom face and at least one side face sloping by less than 180 degrees with respect to the substrate top face;
• depositing said surface layer on a part of said substrate comprising said groove by vacuum chamber sputtering of said material from a sputtering source while moving said substrate in a pattern past said sputtering source in a direction perpendicular to a direction of a main lobe of sputtering from said sputtering source and with a normal to the substrate surface in an angle with said main lobe direction;
• and
• uniformly etching away surface layer material deposited on said substrate by said sputtering until at least a substantial part of said side face is free of said surface layer;
• whereby the pattern becomes defined by said material on the bottom face of the groove.