Measuring apparatus of wafer lower fluid film intermediate variable in CMP process

Abstract

A device for measuring intermediate variable of liquid film under wafer during CMP process, comprising a laser, a spectroscope, a light filter, a camera, a computer for calculating measurement, a polishing slurry feeder for providing polishing slurry containing two fluorescent materials; the laser is connected with a radiation lens via optical fiber, the light exit optical range of the radiation lens covers the liquid film under the wafer, the spectroscope is disposed above the wafer, two filters are disposed on two light exit direction of the spectroscope, each of which is aligned with a camera, the camera is in data connection with the computer, the computer comprises a intermediate variable measuring module for calculating thickness, temperature and pH value via corresponding fluorescent intensity obtained from ratio between two calculated fluorescent intensities. The invention can effectively measure the intermediate variable (such as thickness, temperature and pH value) of liquid film under wafer during CMP process.

Description

technical field [0001] The invention relates to the field of laser measurement, in particular to a measuring device for intermediate variables (polishing liquid film thickness, liquid film temperature, and liquid film pH) of a liquid film under a wafer in a CMP process. Background technique [0002] With the development of VLSI multilayer interconnection technology, it is necessary to implement multilayer wiring structures on silicon wafers, and each layer requires high global flatness to meet etching requirements. In 1990, IBM Corporation took the lead in proposing the chemical mechanical polishing (CMP, Chemical Mechanical Planarization) global planarization technology, which was successfully applied in the production of 64Mb DRAM in 1991. After that, CMP technology developed rapidly. At present, the research and development work of CMP technology has developed to the whole world, and presents a fierce competition momentum. [0003] Although CMP is considered to be the m...

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Problems solved by technology

[0006] In order to overcome the inadequacy of the prior art that cannot measure the intermediate variables under the wafer in the CMP process, the present invention provides a method based on LIF technology that can effectively measure the intermediate variables (such as thickness, temperature, and pH value) under the wafer in the CMP process. Measuring device for intermediate variables under wafer during CMP process

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