Shallow trench isolation structure manufacturing method and NAND flash memory manufacturing method

Abstract

The invention relates to a shallow trench isolation structure manufacturing method and an NAND flash memory manufacturing method. The shallow trench isolation structure manufacturing method includes: providing a semiconductor substrate; sequentially forming a polycrystalline silicon doped layer and a hard mask layer on the semiconductor substrate; subjecting the hard mask layer and the polycrystalline silicon doped layer to patterning; at least forming a protection layer on the lateral side of the rest polycrystalline silicon doped layer; taking the reset hard mask layer and the protection layer as masks to form shallow trenches in the semiconductor substrate by etching; removing the protection layer; filling isolation materials in the shallow trenches; removing the hard mask layer. The NAND flash memory manufacturing method includes the shallow trench isolation structure manufacturing method. Owing to the protection layer preset in a process of etching to form the shallow trenches in the semiconductor substrate, corrosion of the polycrystalline silicon doped layer can be avoided, and accordingly performances of semiconductor devices can be improved.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to a method for manufacturing a shallow trench isolation structure and a method for manufacturing a NAND flash memory. Background technique [0002] The development direction of semiconductor integrated circuits is to increase density and shrink components. In the manufacture of integrated circuits, the isolation structure is an important technology, and the components formed on the silicon substrate must be isolated from other components. With the advancement of semiconductor manufacturing technology, shallow trench isolation (Shallow Trench Isolation, STI) technology has gradually replaced other isolation methods such as local oxidation of silicon (LOCOS) used in traditional semiconductor device manufacturing. [0003] In the prior art, when forming NAND flash memory, it is also necessary to form a shallow trench isolation structure between memory cells, and the method for...

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Problems solved by technology

However, when the shallow trench isolation structure formed by the above method is included in the NAND flash memory, its electrical performance is very poor and the yield rate is very low

[0008] Similarly, when the above-mentioned shallow trench isolation structure formation method is applied to other semiconductor devices, there are also defects of poor electrical performance and low yield

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