Non-ionic ammonium hydrogen fluoride etching solution with low surface tension

Abstract

The invention discloses a non-ionic ammonium hydrogen fluoride etching solution with low surface tension. The non-ionic ammonium hydrogen fluoride etching solution consists of hydrogen fluoride, ammonium fluoride, an additive and deionized water, wherein preferably, the additive is selected from one or more of polyethylene glycol monoperfluorononylene ether, perfluorohexane sulfonic acid polyglycerol ester, octylamine, polyglycerol perfluorononylene ether, polyethylene glycol perfluorononylene methyl ether, and perfluorohexane sulfonic acid macrogol ester. A proper additive is added on the basis of the hydrogen fluoride etching solution in the prior art and can be dissolved into high-concentration hydrogen fluoride and ammonium fluoride without introducing any metal ion or negative ion, so that residues on the surface of an etched oxide layer are eliminated, low surface tension is achieved for the etching solution, the permeability of the etching solution is increased, and the etching solution can enter a pore of which the pore diameter is 2.5 mu m; the fluorocarbon chain of a fluorine surfactant in a surfactant composition has the properties of high surface activity, hydrophobicity and lipophobicity, so that the surface tension of the solution can be reduced greatly, the using amount of the etching solution is small, and the production cost is low.

Description

technical field [0001] The invention relates to the technical field of electronic chemicals in semiconductor and liquid crystal display thin film transistor (TFT) industries, in particular to a non-ionic low surface tension acidic ammonium fluoride etchant used in semiconductor processes and liquid crystal processes. Background technique [0002] A large number of thin films and thin layers are provided on the TFT substrate, so in order to prevent undesired electrical short circuits between them, it is preferable to uniformly incline the cut side of the etched substrate, that is, the etching profile, and make the lower part wider than the upper part, For blunt cone (taper) shape. This is because the difference in height between two or more thin film layers formed when the etching profile is blunt tapered is reduced. Etching methods include dry etching using gas and wet etching using etching liquid. Although wet etching has disadvantages, the equipment investment cost requir...

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Problems solved by technology

The composition of the above etching solution is complex. Compared with the main components of hydrofluoric acid and ammonium fluoride, the amount of surfactant activity is relatively large, and the production cost is high; in addition, when the concentration of hydrogen fluoride and ammonium fluoride in the etching solution is high, generally non- Ionic surfactants are difficult to dissolve, cannot adjust the surface tension of the etching solution, and have relatively weak permeability, making it difficult to etch into very small pores

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