Fluorine surface etchant for semiconductor and preparation method thereof

Abstract

The invention relates to a fluorine surface etching liquid for semiconductors and a preparation method thereof. The etching liquid formula: stabilizer 25-50, hydrofluoric acid 0.2-2, buffer 1-10, nitric acid 2-10, nonionic surfactant 0.0001 -0.001, appropriate amount of deionized water. Process steps: 1. Add buffering agent to hydrofluoric acid according to the proportion, stir for 30 minutes to obtain mixture I, 2. add stabilizer to nitric acid according to the proportion, and stir for 40 minutes to obtain mixture II. 2 Mix the obtained mixtures I and II with an appropriate amount of deionized water, stir for 30 minutes, and then add nonionic surfactant after standing still for 10 minutes, and stir evenly. The etchant prepared by the present invention controls its corrosion strength by adding hydrofluoric acid to the buffer; Adds the etching stability of nitric acid to control the nitric acid by the stabilizer; Reduces the surface tension of the etchant by adding nonionic surfactants, Improve the wetting effect of the etchant, which greatly improves the stability of the product, the smoothness and precision of etching, and improves the yield.

Description

technical field [0001] The invention relates to an etching solution, in particular to a fluorine surface etching solution for semiconductors and a preparation method thereof. It belongs to the technical field of electronic chemicals. Background technique [0002] Wet chemical etching is one of the most common patterning techniques used in semiconductor manufacturing. At present, there are many kinds of etching solutions, up to hundreds, but there are relatively few etching solutions specially used for semiconductors. There are still defects in the stability of the etchant in etching, the smoothness and precision of thin line etching, and the qualified rate of products. In the etching process, due to the influence of the smoothness of the silicon wafer surface, the surface tension of the etching solution, and the width of the lines of the engraved graphics, the current etching solution tends to be in the etching process, especially in the etching process for thin lines. Th...

AI Technical Summary

Problems solved by technology

In the etching process, due to the influence of the smoothness of the silicon wafer surface, the surface tension of the etching solution, and the width of the lines of the engraved graphics, the current etching solution tends to be in the etching process, especially in the etching process for thin lines. The etching is unclear, not in place, or the lines are hooked into a circular arc, or excessive corrosion occurs locally, etc.

The main reason is that the performance of the current etching solution cannot fully meet the process requirements; the second is that the surface tension of the etching solution is too large, and the wettability of the corroded silicon wafer surface is not good enough.