An advanced process control method using time interval between lots of a
particular product to control the weighting of feedback data is described.
A plurality of products are fabricated wherein the products are tracked by
the process control method based on product type, for example. Variation
in a parameter is detected. The adjustment speed of a process recipe is
determined based on a time interval weighting wherein the time interval is
defined as the time between processing of lots of the same product type.
The process recipe is updated at the determined adjustment speed to
decrease variation of the parameter.
