Method for manufacturing CVD silicon oxide capable of improving forming quality

Abstract

The invention provides a method for manufacturing CVD silicon oxide capable of improving forming quality. In the prior art, the CVD silicon oxide is not subjected to thermal treatment for compacting before photoetching and etching processes to cause peeling off of photoresist and serious undercut of the CVD silicon oxide due to small adherence force of the silicon oxide with the photoresist. The method comprises the following steps: firstly, growing the silicon oxide on a silicon substrate through a CVD process; secondly, performing thermal treatment on the silicon oxide to compact the silicon oxide; thirdly, coating the photoresist on the silicon oxide, and carrying out exposure and developing processes to form a graph of the silicon oxide on the photoresist; fourthly, carrying out wet etching process to form the silicon oxide; and finally, removing the photoresist. The method can improve the adherence force between the CVD silicon oxide and the photoreist, and reduce the diffusion velocity of etching fluid between interfaces, thereby reducing the etching velocity of the CVD silicon oxide surface, effectively reducing undercut, and effectively improving the forming quality.

Description

technical field [0001] The invention relates to the field of semiconductor manufacturing, in particular to a CVD silicon oxide manufacturing method capable of improving forming quality. Background technique [0002] Silicon oxide is one of the most widely used insulating dielectrics in the field of semiconductor manufacturing. It can be used as field oxide layer, gate oxide layer and shallow trench isolation structure (STI), etc. Silicon oxide can be produced by thermal oxidation and chemical vapor deposition. (Chemical Vapor Deposition; CVD for short) process, and the silicon oxide produced by it is referred to as thermal oxide silicon oxide and CVD silicon oxide for short. [0003] In the field of semiconductor manufacturing, dilute hydrofluoric acid (Dilute HF; referred to as DHF) or hydrofluoric acid buffered etching solution (Buffered HF; referred to as BHF) is usually used to etch the above-mentioned thermally oxidized silicon oxide and CVD silicon oxide, and the etche...

AI Technical Summary

Problems solved by technology

The undercut of thermally oxidized silicon oxide is not very serious due to its relatively dense texture, while the texture of CVD silicon oxide is relatively loose, and the undercut is very serious after DHF or BHF etching. The tightness causes the photoresist to lift during etching, which affects the forming effect of CVD silicon oxide even more

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