First, tubing breakdown caused by the pump design generates particles, which are detrimental to any semiconductor process. Second, the pumps do not provide consistent flow control and therefore introduce potential process variability. Third, peristaltic pumps require significant maintenance to keep functioning properly, which leads to tool downtime and excessive repair costs. Fourth, the pumps used on most CMP tools do not incorporate any type of closed-loop feedback system. The materials used include elements and additives that can affect processes randomly and unpredictably.
Any extraneous particles introduced into the chemical flow stream can cause defects.
Tubing particle generation during peristaltic pump use. In many cases, flow rates must be changed to optimize a process. Sometimes, these changes may even occur in sequential steps of a process. Therefore, the tool must be able to reliably call for various flow rates. Depending on the process, peristaltic pumps may not be able to deliver the linearity and repeatability required for optimal performance.