Preparation method for plow groove isolation structure capable of avoiding residual silicon oxynitride

Abstract

The invention provides a trench isolation structure manufacturing method capable of avoiding silicon oxynitride residue, wherein the trench isolation structure is manufactured on a silicon substrate. In the prior art, heat processing is carried out before the removal of silicon oxynitride and consequently the silicon oxynitride is compact and can not be removed completely so as to influence the performance of elements and an semiconductor device in an active area. The trench isolation structure manufacturing method capable of avoiding silicon oxynitride residue comprises the following steps: firstly, making a lining oxide layer and a protective barrier layer by laminating a silicon oxynitride layer and a silicon nitride layer up and down on the silicon substrate; secondly, carrying out photoetching and etching an isolating trench; thirdly, making an isolation oxide layer on the trench wall of the isolating trench; fourthly, filling the isolating trench through chemical vapor deposition; fifthly, carrying out a chemical and mechanical polishing process to remove the silicon oxynitride layer to form a trench isolation structure; and finally, removing the silicon nitride layer and the lining oxide layer. The trench isolation structure manufacturing method capable of avoiding silicon oxynitride residue can avoid silicon oxynitride residue, thereby greatly improving the performance of the semiconductor device.

Description

technical field [0001] The invention relates to a trench isolation structure manufacturing process, in particular to a trench isolation structure manufacturing method capable of avoiding silicon oxynitride residues. Background technique [0002] When manufacturing a semiconductor device, it is necessary to separate multiple components of the semiconductor device through a trench isolation structure (a shallow trench isolation structure (STI) is generally used now). The manufacturing method of the trench isolation structure in the prior art comprises the following steps: a, making a pad oxide layer on the silicon substrate for making the semiconductor device; b, making a protective barrier layer on the pad oxide layer, the protective barrier layer Including silicon oxynitride layer and silicon nitride layer stacked up and down; c, photolithography and etching out the isolation trench; d, making an isolation oxide layer on the wall of the isolation trench; e, through a high-de...

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Problems solved by technology

[0003] However, after the trench isolation structure is manufactured by the above method, silicon oxynitride residues will appear on the active regions between the trench isolation s

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