Enhanced control and manufacturing for CMP processing with advanced blending and delivery of slurries

Inhalt:
Ensuring the integrity of CMP slurry is essential to successful control of CMP processing. This includes chemical properties of the slurry: particle size distribution, pH, particle suspension, pot life, concentration, and contamination. All these properties will impact the control of the CMP process, chemical usage, chemical costs, waste, and ultimately yield. A volumetric blending system, based on “U-Tube” technology (patents), has been developed and applied to commercial solutions for blending and delivering CMP slurries in production environments. This new approach is superior to other conventional methods of blending, such as sensors, load cells, metering pumps, vacuums, and flow meters. The “U-Tube” technique allows for highly accurate and repetitive volumetric measurements, and blending of various chemicals. This innovative design naturally controls the level within each measuring vessel. The volume contained in each “U-Tube” is easily adjusted to give the desired chemical volume for mixing. This process provides on-demand blending and delivery closer to the point-of-use, reducing batch size and resultant waste, and providing more freshly mixed materials to the CMP tools. The wide dynamic range of the “U-Tube” volumetric measurement system enables mixing ratios of over 1000 to 1 and high volumetric repeatability for exceptionally low process variance.