Improved silica stain test structures and methods therefor

Abstract

A method for forming silica stain on a substrate to facilitate monitoring of the silica stain during integrated circuit manufacture. The method includes providing a silica stain test structure which has a silicon substrate, a hydrophilic silicon dioxide containing layer disposed above the silicon substrate, and a plurality of cavities formed in the silicon substrate through the silicon dioxide containing layer. The cavities have hydrophobic sidewalls. The method also includes exposing the silica stain test structure to deionized water, and drying the silica stain test structure to form the silica stain on the silicon dioxide containing layer.

Description

Technical field [0001] The invention relates to the manufacture of integrated circuits. In particular, the present invention relates to a method for forming silica stains on a substrate during an integrated circuit manufacturing process, and a silica stain test structure and a manufacturing method thereof. Background technique [0002] In the production of semiconductor integrated circuits, wet chemical reagents are often used during wafer processing. For example, some processing procedures require the patterned wafer to be immersed in a wet, liquid chemical reagent for etching. After the exposed part of the wafer is etched away by the wet chemical reagent, the wafer is taken out, cleaned with deionized water, and then dried. [0003] After cleaning and drying, it was found that silica stains sometimes appeared on the wafer surface. Silica stains are produced by the dissolved silicon dioxide in the cleaning solution, which re-deposit on the wafer surface during the drying process...

AI Technical Summary

Problems solved by technology

[0008] Those skilled in the art will appreciate that the additional processing steps required to detect and / or measure stains formed on prior art silicon monitoring test structures have a number of disadvantages

At a minimum, additional processing would inconvenience the process engineer, who would have to do extra work before the presence and / or amount of silica stain could be detected

Additionally additional processing introduces additional complications, usually measured in additional time and / or expense required

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