Copper etching solution and application thereof in wafer level packaging

Abstract

The invention discloses a copper etching solution. The copper etching solution comprises the following components in parts by weight: 1.0-8.0 parts of organic acid; 0.1 to 4.0 parts of an amine compound containing a carboxylic acid group; 0.001 to 1.0 part of an amide type surface active agent; 0.3 to 3.0 parts of an organic phosphine compound; 1-10 parts of hydrogen peroxide; and 70.0 to 99.0 parts of water. In a certain concentration range, the copper layer on the wafer can be effectively removed by compounding the organic acid, the amine compound containing the carboxylic acid group, the amide type surface active agent, the organic phosphine compound, the hydrogen peroxide and the water. In especial, due to the introduction of the amine compound containing the carboxylic acid group and the amide type surface active agent, the synergistic effect of the amine compound containing the carboxylic acid group and the amide type surface active agent not only reduces the corrosion of metal, but also reduces lateral erosion and controls CD-loss within 300nm, so that effective technical support is provided for manufacturing wafer-level packaging narrow-pitch bumps and fine lines.

Description

technical field [0001] The invention relates to the technical field of etching solution, in particular to a copper etching solution and its application. Background technique [0002] In the field of Wafer Level Package (WLP), when manufacturing a new generation of electrical contacts (such as copper pillars) and metal rewiring processes, a layer of copper seed layer is generally sputtered on the surface of the wafer before electroplating copper , as a conductive layer during electroplating. After that, the circuit pattern will be defined with the help of photoresist by means of exposure and development, and then the wires will be electroplated by electrochemical deposition process. Then the photoresist is removed, and the copper seed layer is removed with a copper etchant, so as to obtain a complete electrical contact or circuit. [0003] The copper etchant used in the field of wafer-level packaging is mainly acidic hydrogen peroxide system. Most of the systems used in th...

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Problems solved by technology

Although the aforementioned copper etchant composition provides a relatively stable copper etchant composition to a certain extent, and the etching rate, service life and other aspects have been discussed in detail, but the amount of side engraving, There is still a lack of in-depth research and improvement on the optimization of etchant in terms of etching uniformity of large-sized wafers

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