Process for producing monocrystalline silicon solar cells with rear-side emitter and base contacts and solar cell, produced by such a process

摘要

The invention relates to a method for producing monocrystalline silicon solar cells with rear-side emitter and base contacts and back surface field near front surface passivation by front surface field, obtained by a simultaneous doping by means of a suitable dopant. According to the invention, a cover layer which is impermeable to phosphorus diffusion is applied over the entire surface of the wafer side provided with diffused, locally structured emitters, whereby the cover layer is selectively removed by means of etching technology in order to provide access to the base regions in the substrate. Furthermore, local depots of a phosphorus dopant are applied in the region of the removed covering layer. In at least one thermal treatment step, a phosphosilicate glass layer is formed on the wafer side opposite the locally structured emitters via a phosphorus-containing gas supplied from the local depots of the neighboring wafer and from additionally supplied phosphorous diffusion of low concentration into the wafer side thermal treatment step, the local phosphor depots react to a silicon and phosphorus-containing layer, diffused from the highly concentrated phosphorus in the wafer surface and the high doping results for the BSF areas.