Functional polycrystalline silicon tunneling silicon oxide passivated contact structure and preparation method thereof

Abstract

A functional polycrystalline silicon tunneling silicon oxide passivated contact structure (TOPCon) and a preparation method thereof are provided. The functional polycrystalline silicon tunneling silicon oxide passivated contact structure includes a crystalline silicon substrate, a nano silicon oxide, and a functional polycrystalline silicon structure laminated in sequence. The functional polycrystalline silicon structure includes a carbon and nitrogen co-doped polycrystalline silicon layer, or alternating layers of a carbon-doped polycrystalline silicon layer and a nitrogen-doped polycrystalline silicon layer. The present invention uses doping engineering to prepare new polycrystalline silicon with different functions, namely, carbon-doped polycrystalline silicon, nitrogen-doped polycrystalline silicon, and carbon and nitrogen co-doped polycrystalline silicon, and forms a functional polycrystalline silicon structure, exerting different functional effects of carbon and nitrogen doped atoms, and simultaneously realizing passivation in the bulk and surface of the silicon wafer, thereby obtaining a TOPCon structure with ultra-high passivation performance.