Method for fabricating shallow-trench isolation structure

Abstract

The invention relates to a method for fabricating a shallow-trench isolation structure, which comprises the following steps: providing a semiconductor substrate in which a trench is formed; performing an oxygen plasma treating process at the trench top; after the oxygen plasma treating process is completed, performing a cleaning process to the trench to remove an oxide layer at the edge of the trench top; and after the cleaning process is completed, filling a dielectric material into the trench. The method can avoid or reduce the formation of defects at the edge of the trench top during the fabrication of the shallow-trench isolation structure.

Description

technical field [0001] The invention relates to the technical field of semiconductor manufacturing, in particular to a manufacturing method of a shallow trench isolation structure. Background technique [0002] With the continuous development of semiconductor integrated circuit manufacturing technology, the device-to-device isolation technology in the semiconductor integrated circuit manufacturing process has also developed from the original local oxidation of silicon (LOCOS) to shallow trench isolation technology. [0003] The shallow trench isolation structure is formed by first forming a trench on a semiconductor substrate, and then filling the trench with an insulating dielectric material. In the Chinese patent application document with publication number CN 1649122A, a manufacturing method of shallow trench isolation is disclosed. Figure 1 to Figure 5 It is a schematic cross-sectional view of the structure corresponding to each step of the manufacturing method of the s...

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Problems solved by technology

[0009] However, in the above STI manufacturing method, weak point defects are often formed at the top edge of the trench of the formed STI structure, and the above wet etching process further deteriorates the weak point defects. , forming sunken defects such as Figure 5 shown in the edge area 25 shown in the

The recess defect will affect the isolation effect and lead to the degradation of the performance of the formed semiconductor device

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