Analysis of Large Particle Count in Fumed Silica Slurries and Its Correlation with Scratch Defects Generated by CMP

2006 ◽  
Vol 153 (5) ◽  
pp. G453 ◽  
Author(s):  
Edward E. Remsen ◽  
Sriram Anjur ◽  
David Boldridge ◽  
Mungai Kamiti ◽  
Shoutian Li ◽  
...  
2007 ◽  
Vol 991 ◽  
Author(s):  
Yun Zhuang ◽  
Yasa Adi Sampurno ◽  
Fransisca Sudargho ◽  
Geoff Steward ◽  
Herbert Barthel ◽  
...  

ABSTRACTIn this study, different amounts of standard fumed silica and fumed silica contaminated by coarse particles was added as powder to a standard copper CMP slurry to investigate their effects on large particle count, mean particle size, slurry viscosity, frictional force during wafer polishing, and copper removal rate. Standard silica powder consisted of the same particles used in the standard slurry while contaminated silica powder consisted of the same particles used in the standard slurry and additional large size particles. Large particle count analysis indicated that slurry dispersion itself generated large size particles in the slurries. The addition of 0.3% and 1% contaminated silica to the standard slurry caused significant increases in large particle count, and the mean particle size increased with the amount of contaminated silica added to the standard slurry. The slurry viscosity generally increased with the amount of standard and contaminated silica added to the standard slurry under the shear rate of 100 s−1. The standard slurry and slurries added with 0.3% and 1% contaminated silica were used to polish 200-mm blanket copper wafers on the APD-500 polisher that has the unique ability to measure frictional force in real time during polishing. The coefficient of friction increased with the amount of contaminated silica added to the standard slurry. In general, the removal rates for the slurry added with 1% contaminated silica were higher than the standard slurry and slurry added with 0.3% contaminated silica.


2009 ◽  
Vol 1157 ◽  
Author(s):  
Bruno Tolla ◽  
David Boldridge

AbstractWe have examined the Large Particle Count (LPC) analytical method to see whether there are opportunities to improve both the accuracy and precision in hope of improving the utility of the LPC measurement. We have identified weaknesses in the current method that limit both its accuracy and its precision, and which can introduce count errors in excess of a factor of 10. We propose modifications to the current method which result in both accuracy and precision improvements. We recommend these improvements as absolutely necessary for any experiments designed to test the correlation between LPC and defectivity.


2005 ◽  
Vol 867 ◽  
Author(s):  
Edward E. Remsen ◽  
Sriram P. Anjur ◽  
David Boldridge ◽  
Mungai Kamiti ◽  
Shoutian Li

AbstractA dual-sensor single particle optical sensing method (SPOS) is described for the measurement of the large particle count (LPC) in fumed silica polishing slurries. LPC values were expressed on a silica sphere-equivalent diameter scale rather than a polystyrene latex-equivalent size basis. Linear correlations between LPC and scratch counts on SiO2 surface films for wafers polished under clean room and table-top CMP conditions are demonstrated. However, these correlations were obtained for a limited set of model slurries; and further investigation will be needed to assess the general applicability of dual-sensor SPOS for oxide scratch defect prediction in CMP slurries.


2010 ◽  
Vol 1249 ◽  
Author(s):  
W. Scott Rader ◽  
Timothy Holt ◽  
Kazusei Tamai

AbstractLarge particles in fumed silica dispersions were characterized by sedimentation, light scattering techniques, Transmission Electron Microscopy (TEM), and lacunarity. Applying centrifugation to fumed silica dispersions generated differences in sedimentation rates of large particles. The sedimentation rates of the large particles were affected by morphological differences and the particles remaining in the supernatant displayed buoyant behavior. The large particle morphology varied from branch like aggregates containing large primary particles to particles comprised of highly coalesced, tightly packed small primary particles. The results indicate the presence of different types of large particles in fumed silica dispersions to which conventional large particle characterization is unable to distinguish.


1965 ◽  
Vol 13 (02) ◽  
pp. 428-438 ◽  
Author(s):  
K Reber ◽  
A Studer

SummaryThis is a comparative study of the methods described by H. P. Wright and O’Brien for determining the adhesiveness of thrombocytes. An attempt is made to characterize and statistically correlate both techniques. With the aid of a Coulter Counter for thrombocyte counts, a normal range is presented for human, rat, and rabbit blood. Anticoagulants used are sodium citrate and Heparin.The influence of Cocaine and the Serotonin antagonist Ro 3-0837 was studied on these same substrates, to determine a pharmacological interference with results of either Wright’s test or O’Brien’s. Both drugs are found to induce a statistically significant increase in the “thrombocyte count” as compared to the corresponding controls. These effects are not real but to be attributed to an increase in particle count due to thrombocyte fragmentation as a consequence of drug application. There is no evidence for the claim that these drugs decrease the adhesiveness of thrombocytes.Numerical results of both tests often show a high and statistically significant correlation, especially following the addition of Ro 3-0837. Such is not true of individual blood samples to which no drug has been added. Evidentally, both tests are not specific for the same characteristic of normal blood platelets. But, when Ro 3-0837 is added, the breakdown of unstable platelets is induced; and the corresponding increase in count of thrombocyte fragments is expressed by both tests in the same fashion.


2014 ◽  
Vol 1025-1026 ◽  
pp. 215-220 ◽  
Author(s):  
Sasirada Weerasunthorn ◽  
Pranut Potiyaraj

Fumed silica particles (SiO2) were directly added into poly (butylene succinate) (PBS) by melt mixing process. The effects of amount of fumed silica particles on mechanical properties of PBS/fumed silica composites, those are tensile strength, tensile modulus, impact strength as well as flexural strength, were investigated. It was found that the mechanical properties decreased with increasing fumed silica loading (0-3 wt%). In order to increase polymer-filler interaction, fumed silica was treated with 3-glycidyloxypropyl trimethoxysilane (GPMS), and its structure was analyzed by FT-IR spectrophotometry. The PBS/modified was found to possess better tensile strength, tensile modulus, impact strength and flexural strength that those of PBS/fumed silica composites.


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