Impact of tool installation delay on factory ramp-up performance

This study examines the effect of delays in tool installation and qualification on plant performance, specified as discounted cumulative cash flow (DCCF) as the plant is ramped from zero to 20,000 wafer starts/month. Two different ramp strategies are addressed-conservative (24 months) and aggressive (9 months). A specific ramp analysis methodology using a discrete event simulator and cost and yield models, applied to the given assumption set, showed: (1) tool qualification delays impacted investment cost by $34 million/month before the fab breaks even and (2) opting for a 62.5% shorter ramp period effected a 19% reduction in break even time.