MOSIS Quality Control
MASK MAKING
Mask vendors are required to perform an automated inspection prior to shipment. For full wafer lithography masks, vendors conduct a die-to-die defect inspection over a sample region of each mask to meet MOSIS' mask defect requirements. For direct-step reticles, vendors perform a full inspection and repair of the reticle.
WAFERS
Process parameters are measured on each lot of wafers by the fabricator's process control monitors, and a set of MOSIS' parametric test structures and yield monitors. Final acceptance of individual wafers is based on this data. Information from these measurements is maintained in statistical quality control charts to help select vendors and to continuously monitor vendor quality. Summary reports of measured data are published for each wafer lot. Defect density information is available upon request.
PACKAGING
MOSIS packagers must follow strict static electricity control procedures and must meet industry visual inspection criteria. A visual inspection is performed before and after die assembly. MOSIS also performs a visual inspection for bond quality and project identity verification. See Packaging Quality Control for further information.