Tanks of semiconductor grade gases (examples include Nitrogen Trifluoride, Sulfur Hexafluoride and Diborane) are changed out once certain pressure or weight limits were detected. Set limits are in place to insure that gas cylinders do not run out in the middle of a production run, and to avoid any possible contaminates released by a nearly empty tank. This project sought to reduce change out level to as low of limits as practical.
A team was formed from environmental, quality control, purchasing and production personnel to set new limits and procedures for tank change out. Meetings were also held with the gas manufacturer (Matheson Gas Products) to discuss recommendations of the team for cylinder limits. Some gases were changed to larger cylinders and higher fill limits to also provide a way of reducing the amount of gas that is wasted and reducing the number of cylinder change outs.
The number of gas cylinders used by two fabrication units was reduced by over 200 per year
Details of Reductions
Additional Information :
The reduction in cylinder use saved Sony over $180,000 in reduced purchases. Reduction in change outs also resulted in the reduction of potential contamination when lines are open. This reduced technician time, improves wafer quality and reduces handling risks