Priority mix planning for cycle time-differentiated semiconductor manufacturing services

Semiconductor fabs often offer manufacturing service of multiple priorities in terms of cycle time-based X-factor targets (XFTs) and fab production must be planned accordingly. This paper studies a priority mix planning (PMP) problem that determines the wafer release rates of individual priorities to maximize fab profit subject to XFT and capacity constraints. It is formulated as a nonlinear programming problem, where the constraints integrate an extended M/G/m:PR queue approximation with contribution theory-based network for modeling how X-factors of individual priorities are affected by priority mix and fab capacity utilization. It is then demonstrated over a realistic fab example that PMP problem can be solved for effectively planning priority mix and machine tool capacity utilization to provide cycle-time differentiated manufacturing services.