A reliable control system for measurement on film thickness in copper chemical mechanical planarization system.

  • Hongkai Li, Zilian Qu, +4 authors Xinchun Lu
  • Published 2013 in The Review of scientific instruments

Abstract

In recent years, a variety of film thickness measurement techniques for copper chemical mechanical planarization (CMP) are subsequently proposed. In this paper, the eddy-current technique is used. In the control system of the CMP tool developed in the State Key Laboratory of Tribology, there are in situ module and off-line module for measurement subsystem. The in situ module can get the thickness of copper film on wafer surface in real time, and accurately judge when the CMP process should stop. This is called end-point detection. The off-line module is used for multi-points measurement after CMP process, in order to know the thickness of remained copper film. The whole control system is structured with two levels, and the physical connection between the upper and the lower is achieved by the industrial Ethernet. The process flow includes calibration and measurement, and there are different algorithms for two modules. In the process of software development, C++ is chosen as the programming language, in combination with Qt OpenSource to design two modules' GUI and OPC technology to implement the communication between the two levels. In addition, the drawing function is developed relying on Matlab, enriching the software functions of the off-line module. The result shows that the control system is running stably after repeated tests and practical operations for a long time.

DOI: 10.1063/1.4833396

Cite this paper

@article{Li2013ARC, title={A reliable control system for measurement on film thickness in copper chemical mechanical planarization system.}, author={Hongkai Li and Zilian Qu and Qian Zhao and Fangxin Tian and Dewen Zhao and Yonggang Meng and Xinchun Lu}, journal={The Review of scientific instruments}, year={2013}, volume={84 12}, pages={125101} }