Manufacturing method of trench isolation structure

Abstract

The invention provides a manufacturing method of a trench isolation structure. The manufacturing method comprises the steps of providing a substrate, forming a patterned mask layer on the substrate, and implementing first etching on the substrate by the patterned mask layer so as to form a trench in the substrate; forming dielectric materials in the groove and the patterned mask layer, wherein the dielectric material on the patterned mask layer has a first height; implementing etching so that the dielectric material on the patterned mask layer is reduced to a second height from the first height; and implementing a planarization process to remove the dielectric material on the patterned mask layer, wherein the planarization process employs a grinding cushion, first pressure is applied to a central part of the grinding cushion, second pressure is applied to an edge part of the grinding cushion, and the second pressure is larger than the first pressure.

Description

technical field [0001] The present invention relates to semiconductor technology, and in particular to a method for manufacturing a trench isolation structure with better height uniformity. Background technique [0002] Isolation structures of semiconductor devices are generally used to separate semiconductor elements such as transistors, resistors, and capacitors in an active region from semiconductor elements in adjacent active regions on the same semiconductor substrate. [0003] At present, commonly used isolation structures include trench isolation structures, in which adjacent active regions are electrically isolated from each other by an isolation dielectric (isolation dielectric) filled in a trench vertically formed in a semiconductor substrate, and the isolation dielectric Usually made of silicon dioxide (SiO 2 )production. A trench is formed in the substrate according to the required pattern of the isolation region, and then an isolation dielectric is formed to f...

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Problems solved by technology

However, the height (or thickness) uniformity of the trench isolation structure is usually not good

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