A high-speed bump electroplating method for copper interconnects

Abstract

The invention discloses a high-speed embossment electroplating method applied to copper interconnection. A sulfonic acid copper system electroplating liquid is adopted to carry out copper column embossment electroplating; the electroplating conditions are as follows: the current density is 1-25A / dm<2>, and the temperature is 15-35 DEG C; the electroplating liquid comprises 160-350g / L high-purity methanesulfonic acid copper salt, 30-180g / L high-purity methanesulfonic acid and 10-80mg / L chloride ions; the electroplating liquid further comprises 1-10ml / L of an accelerator and 1-10ml / L of a leveling agent; the accelerator is UPB3221A and comprises one or a mixture of several of polydithio dipropane sodium sulfonate, alcohlpropane sulfonate, phenyl dithio propane sodium sulfonate, 3-sulfenyl-1-propanesulfonic acid sodium salt and dimethyl-dithio formamide sulfonic acid; and the leveling agent is UPB3221L and comprises one or a mixture of several of polyethylene glycol, a fatty alcohol alkoxy compound, an ethylene oxide-propylene oxide block copolymer of which the molecular weights are respectively 400, 1,000, 6,000 and 20,000. The high-speed embossment electroplating method applied to copper interconnection, disclosed by the invention, ensures that a copper column has good reliability and uniformity, and at the same time has a relatively high electroplating speed.

Description

technical field [0001] The invention relates to an electroplating method for preparing copper bumps on a wafer, in particular to a high-speed bump electroplating method for copper interconnection. Background technique [0002] The traditional interconnection process technology of semiconductor chips is a thin film process of aluminum process. However, when the line width is less than 0.18um, reliability problems such as signal delay and electromigration seriously affect the reliability of integrated circuits. In 1999, IBM took the lead in developing the damascenes chip copper interconnection process, and achieved mass production of the chip copper interconnection process in 2000. Copper metal is considered to be an excellent chip interconnection material due to its excellent electrical conductivity, thermal conductivity, low melting point and easy extension. As the feature size of the chip line width becomes smaller and smaller, the traditional packaging method can no long...

AI Technical Summary

Problems solved by technology

The high-speed bump plating process has not been used industrially due to reliability and uniformity issues

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