Mechanochemical grinding process and method for increasing grinding end point accuracy

Abstract

The invention discloses a grinding terminal precision reinforced method in the chemical mechanical grinding course before grinding, which comprises the following steps: providing testing piece with grinded layer and material layer under the grinded layer; supplying certain wavelength testing beam to illuminate testing piece; proceeding chemical grinding for the testing piece; removing the grinded layer until exposing material layer; detecting reflecting strength of detected beam in the grinding course; judging the removing degree to approach the reflecting strength of interface between grinded layer and material layer; possessing the wavelength detected beam for subsequent grinding course if the reflecting strength is downward increasingly.

Description

technical field [0001] The present invention relates to a chemical mechanical polishing process, and more particularly to a chemical mechanical polishing process and a method for increasing the accuracy of the polishing end point. Background technique [0002] With the vigorous development of semiconductor process technology, the number of transistors that can be produced per unit area on a chip is also increasing, and the integration of components is high. The unevenness of the chip surface cannot be tolerated, and the demand for chip surface flatness is also increasing. increasing. Chemical mechanical polishing can provide good overall surface uniformity, and has become an indispensable thin film planarization technology in deep sub-micron process. [0003] Taking the common chemical mechanical polishing process of tungsten plug as an example, please refer to Figure 1A . Figure 1A It is a cross-sectional view showing the structure of a conventional metal interconnection...

AI Technical Summary

Problems solved by technology

These coatings will cause the reflection intensity of the infrared laser to be less regular than before, and the thickness of the layer to be polished will decrease, but the reflection intensity may increase instead, resulting in disordered reflection intensity

This phenomenon will make it impossible to judge the grinding end point

If the grinding is terminated too early, there will be a residue of the conductor layer 150 on the material layer 120, which may cause a bridging phenomenon (bridge)

On the contrary, if the grinding is terminated too late, it will cause the erosion phenomenon (erosion) of the material layer 120, so that the material layer 120 is ground and thinned at the same time, and the conductor layer 150 is also excessively ground, even in components with higher integration , it will also cause insufficient dielectric material between the metal interconnection lines, which will affect the operation of the components

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