Slurry pump types impact slurry particle size distribution as well as CMP process performance. This paper has two parts. Part 1 is a comparison of two slurry pump types tested on a production CMP oxide slurry distribution system. The performance of a Levitronix® bearingless pumping system (BPS) is compared to a bellows pump. Part 2 is a comparative study of the effects between a point of use bearingless pumping system and a point of use peristaltic pump system tested on a 200mm Novellus Momentum™ CMP oxide tool and a 200mm Applied Materials® MirraMesa™ copper CMP tool.
The BPS pump tested on the oxide slurry distribution system showed a 28 percent reduction in particles at 800nm and better than 50% reduction in particles greater than 1 micron. The BPS point of use system tested on the oxide CMP process showed flatter removal rates above 2000 A/min than the peristaltic pump system. Blanket wafer non-uniformity results were less than 4.5% at slurry flow rates ranging from 20mL/min to 280 mL/min. BPS blanket copper removal rates at 50 mL/min were 2500 A/min higher than the peristaltic pumps. Tantalum blanket wafer non-uniformities were less than 5.7% on slurry flow rates ranging from 50 mL/min to 250 mL/min.