Conducting real time control to chemical mechanical polishing process of measuring shaft deformation

Application Number: 00120454
Application Date: 2000.07.11
Publication Number: 1280049
Publication Date: 2001.01.17
Priority Information: 1999/7/12 US 09/351,436
International: B24B49/10
Applicant(s) Name: International Business Machine Corp.
Inventor(s) Name: Li Leping;Wang Xinhui
Patent Agency Code: 11038
Patent Agent: wang yonggang
Abstract A method and apparatus are described for detecting an endpoint of a film removal process in which a film is removed using a polishing apparatus having a polishing surface connected to a shaft. Deformation of the shaft, resulting from torque caused by friction on the polishing surface, is detected. This detection is performed using either a sensor mounted on the shaft, or by monitoring a phase difference between light signals reflected from two points on the shaft. A signal is generated in accordance with the deformation of the shaft. A change in the signal indicates a change in the torque, thereby indicating the endpoint of the film removal process. This arrangement permits real time and in-situ monitoring and control of the film removal process.