Method for forming shallow groove isolation area

Abstract

A method for forming a shallow groove isolation area comprises the steps of providing a semiconductor substrate comprising a wide line area and a thick line area; sequentially forming a pad oxide layer, a first grinding stopping layer, an etching stopping layer and a second grinding stopping layer on the semiconductor substrate; etching the pad oxide layer, the first grinding stopping layer, the etching stopping layer, the second grinding stopping layer and the semiconductor substrate to form grooves; forming an insulation oxide layer which at least enables the groove to be fully filled; conducting first grinding on the insulation oxide layer until the second grinding stopping layer exposes; removing the second grinding stopping layer; conducting second grinding on the insulation oxide layer until the first grinding stopping layer exposes; removing the first grinding stopping layer; and removing the pad oxide layer. The method can be used for well controlling the height of an isolation structure of a shallow groove and enables the heights of all isolation structures of the shallow grooves to be same.

Description

technical field [0001] The invention relates to the field of semiconductor manufacturing, in particular to a method for forming a shallow trench isolation region. 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. Usually, some areas in semiconductor devices have higher active area density, and the trench width for active area isolation is smaller (<0.2 μm). This area is called "dense line area"; The area density is low, and the trench width for is...

AI Technical Summary

Problems solved by technology

[0009] The process based on the above process has the following two problems, which affect the height of the isolation structure (Step height) between the regions:

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