Single Wafer Management for Non Productive Wafers NPW

Our industry understands quite well that there is more agility and efficiency in the front end wafer fab automation required. Initiatives as the 300 mm prime discussion and about small lot manufacturing (SLM) stand for the challenges of the semiconductor industry for concepts which offer improved productivity. Analysis from major IC manufacturers of state-of- the-art fabs has shown that: 70% of the time a wafer is just waiting - Up to 70% of the wafer cycle time is waiting time. - Only 10% is process time. -NPW ratio vs WIP is higher than 50% - Average filling grade for NPW´s in FOUPS can be only 40% - NPW consumption is often not under control. Above facts are resulting in extremely long cycle times, low process tool utilization and huge waste.