Method for polishing copper by chemical and mechanical methods

Abstract

The invention discloses a chemical mechanical planarization method for copper, which is used for flattening the copper metal layer of semiconductor basements, and includes the following steps: executing first-stage grinding to remove the copper metal layer of semiconductor basements, executing second-stage grinding to remove the barrier layer under the copper metal layer; wherein, the second-stage grinding including the following steps: using grinding agent to carry out main grinding, using corrosion inhibitor to carry out grinding after finishing main grinding, and using deionized water to grinding and washing. The method can reduce or eliminate the corrosion on copper during the process of grinding.

Description

technical field [0001] The invention relates to the technical field of semiconductor manufacturing, in particular to a copper chemical mechanical polishing method. Background technique [0002] With the advancement of semiconductor integrated circuit manufacturing technology, the line width is getting smaller and smaller. In order to reduce the resistance-capacitance delay (RC delay) of the back-end interconnection structure, a dielectric material with a low dielectric constant is used as the dielectric layer, and copper Metal as the material for the interconnection lines; [0003] Because copper metal is difficult to etch, the industry introduces a damascene process or a dual damascene process to manufacture copper interconnection lines; in the manufacturing method of copper interconnection lines, a dielectric layer with a low dielectric constant is first formed; then, an opening is formed in the dielectric layer ; Then, metal copper is deposited in the opening and on the ...

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Problems solved by technology

[0010] In particular, the three steps described in the prior art are often carried out on different grinding pads of the same grinding equipment, and a certain step of grinding is carried out on each grinding pad. To complete the chemical mechanical grinding of copper, the substrate must be sequentially passed through different grinding pads. Grinding pad; the grinding time of each step may be different. Therefore, after the substrate on the grinding pad with a shorter grinding time completes the grinding of this stage, it is necessary to wait for the grinding of the base on the grinding pad of the next step to complete the grinding before entering the next step. The grinding pad of the step; this prolongs the corrosion of copper by deionized water and chemical substances in deionized water, causing defects in the formed copper interconnection lines, affecting the electrical properties and stability of the formed semiconductor devices

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