Polycrystalline silicon film deposition method

Abstract

The invention provides a polycrystalline silicon film deposition method. The method comprises the following steps: a substrate is placed in equipment for depositing polycrystalline silicon films; silane is introduced in the equipment for depositing the polycrystalline silicon films on the substrate, and the polycrystalline silicon films adopt materials of phosphorus-doped polycrystalline silicon;the introduction of the silane is stopped; phosphorane is introduced in the equipment by a period of time; the introduction of the phosphorane is stopped; and the substrate is taken out from the equipment. In the polycrystalline silicon film deposition method, after the polycrystalline silicon film deposition is finished, the silane is closed, the phosphorane is continuously introduced into the equipment by a set flow, and phosphorus decomposed from the introduced phosphorane is doped in silicon, so that the size uniformity of crystalline particles can be improved, and the particle defects onthe polycrystalline silicon films are reduced.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to a method for depositing polysilicon thin films. Background technique [0002] Phosphorus-doped polysilicon films deposited by LPCVD (Low Pressure Chemical Vapor Deposition) technology have been widely used in VLSI (Very Large Scale Integration) manufacturing. LPCVD has the advantages of low deposition temperature, easy control of film composition and thickness, film thickness proportional to deposition time, good uniformity and repeatability, good step coverage, and convenient operation. LPCVD uses a furnace tube machine batch process, one hundred or one hundred and fifty wafers can be placed on a vertical wafer boat at a time, and a fixed amount of special reaction gas is injected from the bottom of the reaction chamber or injected within a set time The quartz tube is passed into the reaction furnace, and the thin film is deposited on the entire wafer surface at the same...

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Problems solved by technology

[0003] However, in the current process of depositing phosphorus-doped polysilicon thin films for floating gates, there may be particle defects. These particle defects cannot be scanned out by the station after the deposition of phosphorus-doped polysilicon thin films, resulting in an impact on product quality.

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