Method of detecting end point and monitoring uniformity in chemical-mechanical polishing operation
US6153116A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 30, 1998 |
| Grant date | Nov 28, 2000 |
| Priority date | — |
| Expiry date | Oct 30, 2018 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB24B49/12
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A method of monitoring the state of chemical-mechanical polishing that can be applied to the polishing of a metallic layer over a substrate. The method includes performing a series of scanning operations while a wafer is being polished to generate multiple reflectance line spectra in each polishing period. The degree of dispersion of the reflectance spectra is then utilized as a polishing index. In this invention, the standard deviation of the reflectance spectra in each period is used as a monitoring index, and the peak value of the standard deviation is used to determine the polishing end point. Surface uniformity is monitored by using the time interval between two time nodes at half the peak standard deviation values. When the distance of separation between the two time nodes is large, it means that the polished surface is not sufficiently flat.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.