Manufacturing method of shallow trench isolation structure

Abstract

The invention discloses a manufacturing method of a shallow trench isolation structure, which comprises the steps that after an isolation oxide pad and a blocking silicon nitride layer are sequentially deposited on a silicon substrate of a semi-conductor device, a shallow trench isolation tank is formed on the silicon substrate of the semi-conductor device through a lithography process and an etching process; a substrate silicon oxide layer is grown on the surface of the shallow trench isolation tank; a silicon nitride layer is deposited on the substrate silicon oxide layer; a silicon dioxide layer is deposited on the surface of the silicon nitride layer, and the shallow trench isolation tank is fully filled; and after the height of the silicon dioxide layer which is etched through a dry process reaches the height of the shallow trench isolation structure and the silicon nitride layer and the substrate silicon oxide layer on the blocking silicon nitride layer are sequentially removed, the surface of the silicon substrate is polished through a chemical mechanical process, the shallow trench isolation structure is obtained and the isolation oxide pad is removed. The shallow trench isolation (STI) structure which is manufactured through the method not only avoids the phenomenon of defects, but also avoids a gap in the STI structure.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to a method for manufacturing a shallow trench isolation (STI) structure. Background technique [0002] In the manufacturing process of the semiconductor device, the manufacturing of the STI structure is included. The fabrication of the STI structure is the isolation region between the active regions fabricated on the substrate of the semiconductor device. The manufacturing method of the STI structure is mainly divided into three steps: etching of the STI groove, filling of the STI material, and planarization of the STI structure. The existing method of manufacturing the STI structure will be described in detail below. [0003] figure 1 A flow chart of a method for making a shallow trench isolation structure provided for the prior art, combined with Figure 2a ~ Figure 2d The schematic diagram of the shallow trench isolation structure shown in the figure is illustrated, an...

AI Technical Summary

Problems solved by technology

However, there is also a defect in this method: in the process of depositing the oxide layer 40 in step 103 and filling the STI trench 20, the blocking nitride layer 102 and the isolation oxide pad 101 are etched back to cause the blocking nitride layer 102 and There is a step difference between the isolation oxide pad 101 and the underlying substrate 10, so there will be a filling gap in the middle of the STI groove 20, which will cause a gap to appear in the final formed STI, which will affect the isolation effect of the semiconductor device and seriously cause the semiconductor device to fail.

Images