Shallow trench isolation structure and forming method thereof

Abstract

The invention discloses a forming method of a shallow trench isolation structure, comprising the steps: providing an substrate; forming a stop layer on the substrate; defining a shallow trench graph on the substrate; forming a trench in the substrate on which the stop layer is formed; depositing protective dielectric layers on the stop layer and the trench; corroding the protective dielectric layers until the protective dielectric layer on the stop layer is removed; depositing filler on the stop layer and in the trench; performing planarization process on the substrate where the filler is deposited; eliminating the stop layer on the substrate; and processing the filler by a method of wet etching. The invention also discloses the corresponding shallow trench isolation structure. The shallow trench isolation structure and the forming method thereof can prevent pits occurring at the edges of the shallow trench isolation structure, thereby the forming quality of the shallow trench isolation structure and the yield of devices are improved.

Description

technical field [0001] The present invention relates to the technical field of semiconductor manufacturing, in particular to a shallow trench isolation structure and a method for forming the same. Background technique [0002] With the continuous reduction of the feature size of semiconductor devices, the isolation area between devices is correspondingly reduced, and the requirements for device isolation are getting higher and higher. The local field oxidation isolation technology (LOCOS, Local Oxidation of Silicon) used in the early stage It will form a "bird's beak" (BIRD'S BEAK) region at the boundary of the active region, and the problems such as the expansion of the separation region have been gradually replaced by Shallow Trench Isolation (STI). Using the STI technology to prepare an isolation region to achieve isolation between devices has the advantage that the line width of the active region can be used most effectively and the integration degree can be improved. ...

AI Technical Summary

Problems solved by technology

[0014] The present invention provides a shallow trench isolation structure and its forming method to improve the phenomenon that the filler of the existing shallow trench isolation structure tends to have edge depressions after wet etching

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