Method for electroplating copper

Abstract

The invention provides a method for electroplating copper, and is applicable to electroplating equipment to deposit a copper electroplating layer in a channel of a wafer. The method for electroplating the copper comprises an initial stage, a second stage, a third stage, a fourth stage and the three stages of an excessive electroplating stage; and compared with the prior art, the third stage and the fourth stage are added, the rotation speed range of the wafer is increased in the initial stage while the range of electroplating current is kept unchanged, in the second stage, the third stage and the fourth stage, the rotating speed range of the wafer is kept unchanged while the range of the electroplating current is adjusted in a section-by-section mode, and the rotation speed range of the wafer and the range of the electroplating current are kept unchanged in the excessive electroplating stage. The method for electroplating the copper has the beneficial effects that technology is simple and low in cost, and finally, under the condition of the same type of the electroplating equipment and a same additive system, filling requirements of both a large-size channel and a small-size channel are met, so that a hole defect is avoided when the large-size channel is filled.

Description

technical field [0001] The invention relates to the technical field of semiconductor device manufacturing, in particular to a method for electroplating copper. Background technique [0002] In order to form copper wiring on a semiconductor wafer, it is necessary to fill vias or trenches of wiring (LSI) patterns formed on the semiconductor wafer using a copper electroplating process. [0003] The method for forming metal interconnection lines (copper wiring) in the prior art comprises the following steps: [0004] Step 11, by physical vapor deposition (PVD) method, on the bottom and sidewall of the trench, on the bottom and sidewall of the connection hole, sputter to form a barrier layer, for example, made of tantalum nitride (TaN) and tantalum (Ta) formed stacked barrier layer. The above stacked barrier layer composed of TaN and Ta is only one specific embodiment, obviously, there are many other realization methods for forming the barrier layer. [0005] Step 12, forming ...

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Problems solved by technology

[0007] In step 13, additives are added to the solution used for electroplating copper. The additives are organic substances. During the electroplating process, they may be adsorbed to the inside of copper, so that the gaps between the lattices inside the copper become larger. In the advanced copper plating process, many voids will appear in the copper plated by the electroplated wafer. When there are many small voids in the copper, after the grinding is completed, the surface will be left with pits and pits, which will affect the The performance of the product in terms of electrical conductivity will ultimately affect the yield of the product

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