Method for producing a metal contact structure of a photovoltaic solar cell

A method for processing a metallic contact structure of a photovoltaic solar cell,

• comprising the following method steps:
• A applying an electrically non-conductive insulating layer (2) to at least one of a surface of a semiconductor substrate, or one or more intermediate layers covering said surface,
• B applying a metallic contact layer to at least one of the insulating layer (2) or one or more intermediate layers covering the insulating layer (2), and
• producing one or more local electrically conductive connections between semiconductor substrate (1) and contact layer through the insulating layer (2),
• wherein in method step B the metallic contact layer is formed in a manner comprising the following method steps:
• B1 a first paste containing metal particles is applied at a plurality of local regions,
• B2 a second paste containing metal particles is applied areally, in a manner at least partly covering at least the local regions covered with the first paste and also regions situated therebetween, and
• B3 globally heating the semiconductor substrate and at least the first and second pastes in a temperature step,
• wherein the first paste and the second paste (4a, 4b) and also the temperature step or further temperature steps following method step B1 are designed such that the first paste (3a, 3b) penetrates through the insulating layer (2) and forms an electrically conductive contact directly with the semiconductor substrate (1), whereas the second paste (4a, 4b) does not penetrate through the insulating layer (2) and is electrically conductively connected to the semiconductor substrate (1) only indirectly via the first paste (3a, 3b).