Chemical mechanical planarization (CMP) slurry quality control process and particle size distribution measuring systems
USRE39783E1 · kind E1 · reissue
Assignee
Inventors
Key dates
| Filing date | Aug 12, 2003 |
| Grant date | Aug 21, 2007 |
| Priority date | — |
| Expiry date | Aug 12, 2023 |
Classification
- Technology area (CPC —)General
Abstract
A sensitive particle distribution probe uses special processing including a modified Twomey/Chahine iterative convergence technique and a specially constructed sample cell to obtain particle size distribution measurements from optically dense slurries, such as the slurries used in the semiconductor industry for chemical mechanical planarization. Spectral transmission data is taken over the spectral range of 0.20-2.5 microns, utilizing specially constructed, chemically resistant sample cells of 50-2000 microns thickness, and miniature, fixed grating, linear detector array spectrometers. At wavelengths greater than one micron, the preferred design utilizes InGaAs linear detector arrays. An ultrasonic disrupter can be employed to breakup harmless soft agglomerates. In addition to direct particle size distribution measurement, the invention described here could be used to detect other fundamental causes of slurry degradation, such as foaming and jelling. The probe accomplishes continuous, real time sampling of undiluted slurry. A three-position chopper allows automated operation in an industrial environment without the need for frequent reference spectra, which would require taking the…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.