CPC G03F 7/70641 (2013.01) [G03F 7/70625 (2013.01); G03F 7/70633 (2013.01)] | 8 Claims |
1. A non-transitory computer-readable storage medium that records a data structure for storing data controlling an operation of an overlay measurement device that measures an error between a first overlay mark and a second overlay mark formed on different layers of a wafer, the data, comprising:
information of a recipe that is input to allow the overlay measurement device to measure characteristics of a wafer through a manager program installed in a user terminal, and unique information of the overlay measurement device,
wherein the overlay measurement device comprises
a light source,
an objective lens that concentrates a beam from the light source on a measurement position of the wafer, and gathers the beam being reflected in the measurement position,
a lens focus actuator that adjusts a distance between the objective lens and the wafer such that a focus surface is placed at the first overlay mark or the second overlay mark,
an auto focus module that adjusts a focus by adjusting the lens focus actuator,
a detector that acquires an image of the first overlay mark and an image of the second overlay mark,
a transceiver, and
a processor electrically connected to the transceiver, and
wherein the processor is configured to
obtain the data transmitted from the user terminal through the transceiver,
analyze the recipe included in the data,
when the analysis of the recipe is completed, perform optimization process for measurement options of the wafer based on the recipe,
perform a focus scan at one site by controlling the auto focus module,
determine a focus measurement area based on the performed focus scan,
calculate statistical values for a plurality of parameters by moving the focus by one step within the determined focus measurement area for each site,
apply a weight respectively to the calculated statistical values, and
perform a focus optimization process of selecting a focus from the moved foci where a total of the statistical values to which the weight is applied respectively is a minimum value as a focus of the auto focus module.
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