Method for improving defect of polysilicon

Abstract

A polysilicon defect improving method comprises the following procedures that: a silicon dioxide layer is formed on a silicon substrate; a polysilicon attaching plug is formed on the silicon dioxide layer and runs through the silicon dioxide layer; a silicon nitride layer is formed on the silicon dioxide layer and is covered with the polysilicon attaching plug; an interlevel medium layer is formed on the silicon nitride layer; the interlevel medium layer on the upper part of the polysilicon attaching plug is etched to form an opening; the silicon nitride layer in the opening is etched to expose the polysilicon attaching plug; the opening is filled with polysilicon and is communicated with the polysilicon attaching plug. Through the procedures, the reaction between thermal standard cleaning liquid No 1 and the polysilicon attaching plug can not be produced because of the protection of the silicon nitride layer; as the silicon nitride layer is etched finally, therefore, the silicon nitride layer is not exposed to make the subsequent filling flat.

Description

technical field [0001] The invention relates to a manufacturing method of a semiconductor storage device, in particular to a method for improving polysilicon defects in the capacitance process of a dynamic random access memory. Background technique [0002] DRAM is a widely used integrated circuit component. Most of the DRAMs commonly used in production lines are composed of a transistor and a capacitor. Capacitors are used to store charges to provide electronic information, and they should have a large enough capacitance to avoid data loss and reduce the frequency of charging updates. [0003] With the continuous increase of integration in the integrated circuit manufacturing process, it has become a trend to increase the integration density of DRAM. However, the higher the density of DRAM storage cells, the area that capacitors can use in DRAM storage cells smaller. In order to reduce the area of ​​capacitors while still maintaining a reliable standard, it is important ...

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Problems solved by technology

[0012] The problem solved by the present invention is to provide a method for improving polysilicon defects, to prevent the inability to etch the nitriding due to hot standard cleaning solution No. 1 (HSC1) and buffered oxide etching solution (BOE) when etching the interlayer dielectric layer. Silicon layer, resulting in the residue of the silicon nitride layer, which will cause voids or unevenness when the subsequent film is filled; at the same time, because the hot standard cleaning solution No. 1 (HSC1) will react with the polysilicon plug, resulting in defects in the polysilicon plug , leading to electrical failure

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