METHOD FOR PRODUCING CERAMIC PASSIVATION LAYERS ON SILICON FOR SOLAR CELL MANUFACTURE

• Main Authors: RODE, KLAUS, WIEZER, HARTMUT
• Format: Patent
• Language: English; French; German
• Published: 11.05.2011
• Subjects: BASIC ELECTRIC ELEMENTS; CHEMICAL SURFACE TREATMENT; CHEMISTRY; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY IONIMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; DIFFUSION TREATMENT OF METALLIC MATERIAL; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; METALLURGY; SEMICONDUCTOR DEVICES; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION

The invention relates to a method for producing passivation layers on crystalline silicon by a) coating the silicon with a solution containing at least one polysilazane of the general formula (1): -(SiR'R''-NR''')-n, wherein R', R'', R''' are the same or different and stand independently of each other for hydrogen or a possibly substituted alkyl, aryl, vinyl, or (trialkoxysilyl)alkyl group, wherein n is an integer and n is chosen such that the polysilazane has a number average molecular weight of 150 to 150,000 g/mol, b) subsequently removing the solvent by evaporation, whereby polysilazane layers of 50-500 nm thickness remain on the silicon wafer, and c) heating the polysilazane layer at normal pressure to 200-1000° C. in the presence of air or nitrogen, wherein upon tempering the ceramic layers release hydrogen for bulk passivation of the silicon.