Trench isolation structure and forming method for same

Abstract

Disclosed are a trench isolation structure and a forming method for the same. The trench isolation structure comprises a semiconductor substrate and trenches formed on the surface of the semiconductor substrate, and dielectric layers made of crystal materials are filled in the trenches. By the aid of the trench isolation structure, the sizes of side trenches can be reduced, and the performance of a semiconductor device is improved.

Description

technical field [0001] The invention relates to the field of semiconductor manufacturing, in particular to a trench isolation structure and a forming method thereof. Background technique [0002] As the semiconductor technology enters the deep submicron era, shallow trench isolation structures (STI) are mostly used for isolation between active areas of semiconductor devices such as implanted MOS transistors. The specific formation process mainly includes: forming a shallow trench on the semiconductor substrate by etching and other processes, and the shallow trench is used to isolate the active region on the semiconductor substrate; after that, filling the shallow trench with a dielectric material, The dielectric material fills the shallow trench and covers the surface of the semiconductor substrate; finally, the dielectric material is planarized until the surface of the semiconductor substrate is exposed, and the method of planarization may be chemical mechanical polishing....

AI Technical Summary

Problems solved by technology

However, due to the influence of subsequent steps such as the planarization process and the cleaning process after planarization, in the shallow trench isolation structure of the prior art, there will be an orientation between the surface of the dielectric layer 11 and the surface of the adjacent semiconductor substrate 10 . The lower recessed area is called the side ditch (Divot) 12, and the side ditch is easy to cause problems such as leakage current, which affects the performance of semiconductor devices.

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