Calibrating method and device for online membrane thickness measuring system

Abstract

The invention discloses a calibrating method for an online membrane thickness measuring system. The method comprises the following steps of: detecting polishing pressures on a plurality of wafers, and polishing the plurality of wafers in preset degrees respectively when the polishing pressures reach a preset pressure value; after polishing is completed, acquiring on-wafer voltage and off-wafer voltage of each wafer respectively, and computing a difference value between the on-wafer voltage and the off-wafer voltage; measuring the coating thickness value of each wafer after polishing is completed; correlating the difference value between the on-wafer voltage and the off-wafer voltage of each wafer and the corresponding coating thickness value of each wafer after polishing is completed to generate a voltage difference value-membrane thickness calibration table; and calibrating the coating thickness of the online membrane thickness measuring system according to the voltage difference value-membrane thickness calibration table. The invention further discloses a calibrating method for the online membrane thickness measuring system. According to the invention, the coating thickness can be calibrated quickly and accurately with different polishing processes.

Description

technical field [0001] The invention relates to the technical field of chemical mechanical polishing of integrated circuits, in particular to a calibration method and a calibration device for an online film thickness measurement system. Background technique [0002] In IC (Integrated Circuit, integrated circuit) manufacturing technology, with the continuous improvement of product performance, the requirements for surface quality are getting higher and higher. As the basic material of integrated circuit chips, silicon wafers have surface roughness and surface flatness as one of the important factors affecting the etching line width of integrated circuits. Polishing is an important means of surface planarization. The CMP (Chemical mechanical polishing, chemical mechanical polishing) process is the most widely used global planarization technology, and occupies an important position in the IC manufacturing technology. CMP is a combined technology of mechanical grinding and che...

AI Technical Summary

Problems solved by technology

At present, the wafer size has reached a diameter of more than 300mm, and the characteristic line width has reached below 45nm. The delay of copper interconnection limits the development of IC to a higher speed.

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