Particle Measuring Systems, Inc.

Scott Waisanen

Todd A Cerni

Daniel Rodier

Dennis J Knowlton

Brian A Knollenberg

Dale Griffin

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 probe off-line. In other embodiments, the invention provides a quality control and/or particle size measuring system for CMP slurries using transmission data through an as-used CMP slurry flow. The process of the invention detects transmission through the flow, at select wavelengths, and determines changes in the logarithmic slope of transmission versus wavelength to detect acceptable or unacceptable CMP slurries. The process can further determine CMP slurry particle size through empirical extinction data stored in memory.

Chemical mechanical planarization (CMP) slurry quality control process and particle size distribution measuring systems

A molecular contamination monitoring system includes a piezoelectric measurement sensor exposed to a molecular constituent to be measured; a piezoelectric reference sensor; and a filter for filtering said molecular constituent, the filter located between the reference sensor and the measurement environment. The reference sensor is exposed to the same ambient conditions of temperature, pressure and humidity as the measurement sensor. Alternatively, there may be a plurality of different reference sensors having different filters, or there may be a plurality of different measurement sensors.

System and method for measuring molecular analytes in a measurement fluid

A flow-through monitor for detecting molecular contamination (MC) within a fluid flow. The monitor has a diffusion chamber having an inlet port and an outlet port, and a structure for supporting a fluid flow from the inlet port to the outlet port. The structure includes a flow gap causing a diffusion of molecular contaminants into the diffusion chamber, while substantially preventing, for a rate of the fluid flow above a predetermined magnitude, particulate contaminants within the fluid from entering the diffusion chamber. A SAW device detects molecular contamination interior to the diffusion chamber. Fluid input to the flow-through monitor may be diluted by a pure fluid for extended monitor life. A system for aggregate sampling connects an ensemble manifold upstream of the flow-through monitor. A system for triggered sampling connects a sample preconcentrator downstream of the flow-through monitor. A chemically selective membrane may be located between the flow gap and the SAW. A test surface adapted to collect MC and located to sample the same fluid as the SAW may also be combined with the monitor. A chemical filter and/or heater may be located upstream of the flow-through monitor and valved to the monitor alternately to the unfiltered and unheated sample.

Molecular contamination monitoring system and method

A very 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 50-250 microns thickness, and miniature, fixed grating, linear detector array spectrometers. At wavelengths greater than 1 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 probe off-line.

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Louisville, CO, United States of America

Scott Waisanen