METHOD FOR ELECTRICAL PASSIVATION OF SURFACE OF MONOCRYSTALLINE SILICON Russian patent published in 2015 - IPC H01L21/312 H01L21/288 C30B33/04 C30B29/06 B32B3/00 B82B3/00 B82Y40/00 

FIELD: chemistry.

SUBSTANCE: method for electrical passivation of the surface of silicon with a thin-film organic coating of polycationic molecules includes preparing a substrate for generating an effective negative electrostatic charge, preparing an aqueous solution of polycationic molecules, adsorbing the polycationic molecules on the substrate for 10-15 minutes, washing with deionised water and drying the substrate with the deposited layer in a current of dry air, wherein the substrate used is monocrystalline silicon with a transparent tunnelling layer of silicon dioxide with roughness less than or comparable to the thickness of the formed coating; preparation of the silicon substrate is carried out by boiling at 75°C for 10-15 minutes in a solution of NH₄OH/H₂O₂/H₂O in volume ratio of 1/1/4; the aqueous solution of polycationic molecules is prepared using polyethylene amine, and during adsorption of polycationic molecules on the substrate, the substrate is illuminated on the side of the solution with light with intensity in the range of 800-1000 lx, which is sufficient to alter the charge density of the surface of the semiconductor structure during adsorption.

EFFECT: reduced density of surface electronic states and longer effective lifetime of nonequilibrium charge carriers.

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