Semiconductor device and manufacturing method thereof

Abstract

An embodiment of the invention discloses a semiconductor device and a manufacturing method thereof. The manufacturing method includes forming a nitride layer, trenches of a thin line region and trenches of a thick line region are formed on a substrate; forming a first insulation layer on the bottoms and side walls of the formed trenches of the thin line region and the trenches of the thick line region; removing part of or total of the first insulation layer on the trenches of the thin line region only; depositing a second insulating layer to fill the trenches of the thin line region and the trenches of the thick line region; according to chemical mechanical planarization technology, planarizing the second insulation layer outside trenches of the thin line region and the trenches of the thick line region by utilizing the nitride layer as a barrier layer. Since the part of or the total of the first insulation layer at the bottom of the thin trench region is removed in the manufacturing method, deposition rate of the second insulation layer in the thin trench region is increased, difference of the second insulation layer deposited in the thin line region and the thick line region is reduced, and dishing defect caused in the chemical mechanical planarization process is relived or eliminated.

Description

technical field [0001] The present disclosure relates to the field of semiconductor device manufacturing, in particular to a semiconductor device with a shallow trench isolation structure and a manufacturing method thereof. Background technique [0002] As the integration level of semiconductor devices continues to increase, isolation techniques for electrically isolating adjacent devices become more and more important. The shallow trench isolation process is an isolation technology widely used in the manufacture of highly integrated semiconductor devices. [0003] The shallow trench isolation process realizes effective isolation of the active region by forming an isolation trench defining an active region on a semiconductor substrate and filling the isolation trench with an insulating material. Generally, some areas in semiconductor devices have higher density of active areas, and the width of trenches for isolation of active areas is smaller. This area is called "dense li...

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However, this results in a portion of the deposited insulating laye

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