Use of copper Dimashg process in production of integrated circuits

Abstract

The method comprises: based on the flat surface of photosensitive material and the polysilicon etch-back technology, a selective etch is made for the tantalum nitride and tantalum metal layer deposited with physical vapour deposition process; a one time metal copper chemical mechanical polishing is used to replace the original two times polishing process, copper chemical mechanical polishing and tantalum nitride / tantalum metal layer polishing. The invention reduces the dishing of metal wire and the erosion of insulation media caused by over-polishing from multi times of chemical mechanical polishing.

Description

technical field [0001] The invention belongs to the field of integrated circuit manufacturing technology, and in particular relates to a manufacturing method using copper damascene back-end technology in integrated circuit production. Background technique [0002] With the continuous improvement of integrated circuit manufacturing technology, the volume of semiconductor devices is becoming smaller and smaller, which makes the parasitic capacitance between metals more and more large. For microprocessors, the chip speed is mainly limited by the resistance and Parasitic capacitance is generated. As a result, problems such as resistance-capacitance time delay, mutual interference between signals, and energy loss have become increasingly prominent. In order to solve the problem of resistance-capacitance time delay, the industry's response has always been to use low-dielectric materials (dielectric constant 2.0 to 4.0), so that the dielectric constant of the dielectric layer betw...

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Problems solved by technology

[0012] However, since each layer of Damascus will use metal chemical mechanical polishing twice (copper chemical mechanical polishing and tantalum nitride / tantalum metal layer chemical mechanical polishing), multiple polishing and to ensure that there is no residual copper and barrier metal between metal connections The over-polishing process will bring considerable negative effects, leading to adverse reactions of copper metal wire depression (Disshing) and metal / insulation medium corrosion (Erosion), and especially in the tantalum nitride / tantalum metal chemical mechanical polishing process, In order to ensure good insulation performance, a considerable degree of over-polishing is required, resulting in obvious corrosion (Erosion) of the metal / insulating medium. Therefore, the reverse etching process is used to replace the tantalum nitride / tantalum metal chemical mechanical polishing process, only Using single copper chemical mechanical polishing can greatly improve the performance of the polishing process and improve product yield

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