Copper Plating Method

Abstract

The invention discloses a method for electroplating copper. In the method, stage-type electroplating technique is adopted for treatment, namely, the electroplating technique for treatment is carried out in different stages under the conditions of different current densities, rotating speeds of a silicon wafer, flow rates of electroplate liquid and technical positions of the silicon wafer, so that high filling speed can be guaranteed, the step height with a large size and depth figure is effectively reduced compared with an area without the figure, the thickness of a copper film needed by the electroplating technique can be indirectly reduced on the premise of guaranteeing a chemically mechanical polishing process window, the electroplating technique time and the chemically mechanical polishing process time are further reduced, and the chemical materials are saved.

Description

technical field [0001] The invention relates to the technical field of semiconductor technology, in particular to a copper electroplating method. Background technique [0002] As individual devices become smaller and smaller and integrated circuits run faster and faster, traditional aluminum manufacturing processes can no longer meet the requirements. Therefore, copper interconnection technology has developed into the mainstream semiconductor integrated circuit interconnection technology, and copper electroplating technology It outperforms traditional film-forming processes such as PVD and CVD, and becomes the main process for preparing copper films in copper interconnection technology. [0003] At the same time, as the concept of the Internet of Things heats up, radio frequency chips have gradually become a hot spot in the market. For chips prepared by traditional CMOS technology, its high-frequency performance is relatively general, and it is necessary to use an external ...

AI Technical Summary

Problems solved by technology

[0008] However, the existing stepped electroplating process technology lacks control over large-size (5-100 micron) patterns. Because the electroplating copper deposition rate of large-size patterns is slow, the step height relative to the non-patterned area increases

For the chemical mechanical polishing process, the step height of the large-size pattern relative to the non-pattern area determines the over-throwing amount of the area. The larger the step height is, the greater the over-throwing amount is. Therefore, the thickness of the copper layer must be increased to control the over-throwing amount. Throwing amount, so as to meet the design requirements (the thickness of the copper layer retained in the pattern reaches the standard), which increases the burden on the electroplating process and chemical mechanical polishing process

[0009] Since copper interconnect inductors are mainly large-scale (1-50 micron) and large-depth (1-5 micron) patterns, a copper film with a thickness of several microns is required, which will significantly increase the burden on the electroplating process and chemical mechanical polishing process

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