Chemical mechanical polishing method

Abstract

The invention provides a method for forming a groove structure filled with metal. The method comprises the following steps of: provides a semiconductor substrate and depositing an etching termination layer, a second insulating layer and a first insulating layer sequentially on the semiconductor substrate; coating a photoresist layer on the surface of the first insulating layer and exposing development to pattern the photoresist layer, wherein the opening of the patterned photoresist layer is used for defining the position of the groove; etching the first insulating layer and the second insulating layer sequentially by using the patterned photoresist layer as a mask and stopping etching the etching termination layer to form the groove; and filling the metal in the groove, wherein the metal is higher than the first insulating layer. The invention also provides a groove structure formed by the method and a chemical mechanical polishing method applicable to the groove structure. By the invention, the resistance uniformity of metal square blocks among wafers is improved in the chemical mechanical polishing process.

Description

technical field [0001] The invention relates to the technical field of semiconductor manufacturing, in particular to a chemical mechanical polishing method. Background technique [0002] At present, with the wide application of electronic equipment, the manufacturing process of semiconductors has been developed rapidly. In the manufacturing process of semiconductors, chemical mechanical polishing process (CMP) is involved. [0003] The planarization process of wafer (wafer) is completed by chemical mechanical polishing machine, which can be used for grinding various materials, such as polysilicon, copper, tungsten, shallow trench isolation (STI), Grinding of interlayer dielectric layer (ILD) or intermetal dielectric layer (IMD), etc. Schematic diagram of the cross-sectional structure of the existing chemical mechanical grinding machine, such as figure 1 shown. The machine includes a polishing table 101 , a polishing pad (pad) 102 and a polishing head 103 . The grinding t...

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Problems solved by technology

[0009] Because the grinding time of the wafer on the third grinding table is set according to the experimental value, its specific grinding process cannot be monitored, and more importantly, the grinding head and the grinding pad will be gradually worn out during the grinding process. After using for a period of time, it needs to be replaced regularly. The grinding head or grinding pad used at different times will cause the grinding rate to change. Therefore, if it is still under the predetermined grinding time, it will inevitably lead to excessive grinding on some wafers and excessive grinding on some wafers. Has not been ground to a predetermined thickness, so wafer-to-wafer (WTW) thickness uniformity will be poor

Furthermore, the metal copper is required to reach a certain square resistance value (Rs) after passing through the third grinding table, that is, it is required Figure 4 The metal copper in the middle trench has a predetermined height (measured on a thickness measuring machine), so the uniformity of Rs from wafer to wafer is also poor

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