Deep trench isolation technical method

Abstract

The invention discloses a deep trench isolation technical method. The method comprises that a silicon oxide layer and a silicon nitride layer are formed in the surface of a semiconductor substrate successively; a photoresist is defined to etch the silicon oxide layer and the silicon nitride layer, an area to form a deep trench is opened, and the trench of certain depth is formed by etching downwards; a linear oxide layer is formed in the trench, and polycrystalline silicon is filled; polycrystalline silicon is etched back; a furnace tube is oxide to form a silicon oxide layer; the silicon oxide layer and the silicon nitride layer are removed; epitaxial growth is carried out; the silicon oxide layer is formed; polycrystalline silicon is filled; the polycrystalline silicon in the epitaxial surface and the deep trench are etched back; and the silicon oxide layer in the epitaxial surface is removed by etching. According to the technical method, part depth of trench is formed before epitaxial deposition technology, the subsequent trench is formed by using the characteristic of selective growth of the epitaxial deposition technology, the difficulty of dry etching is reduced, challenge totrench pore-filling is reduced, and a zero-layer mask can be omitted.

Description

technical field [0001] The invention relates to the field of semiconductor device manufacturing, in particular to a deep trench isolation process method for nodes below the 0.18 μm BCD process. Background technique [0002] Trench filling is a particularly critical step in semiconductor manufacturing. At present, silicon dioxide and its derivatives are widely used in trench filling due to their good film properties. Traditional preparation techniques include spin coating (Spin on Glass), sub-atmospheric pressure chemical vapor deposition (SACVD: Sub Atmosphere Chemical Vapor Deposition), plasma chemical vapor deposition (PECVD: Plasma Enhanced Chemical Vapor Deposition) and high-density plasma chemical vapor deposition. Vapor deposition method (HDPCVD: High Density Plasma Chemical Vapor Deposition), etc. The usual trench structure has a depth of no more than 1 micron and an opening of less than 0.25 micron (the size of the opening is fixed). Such a structure can be filled ...

AI Technical Summary

Problems solved by technology

The traditional process has great challenges for dry etching and subsequent trench filling

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