OVERLAY MEASUREMENT OF PITCH WALK IN MULTIPLY PATTERNED TARGETS

摘要

Multiply patterned metrology targets and target design methods are provided to enable pitch walk measurements using overlay measurements. Multiply patterned structures having single features or spacers produced simultaneously and sharing a common pitch with the paired features or spacers are used to express pitch walk as a measurable overlay between the structures. For example, targets are provided which comprise a first multiply patterned structure having a single left-hand feature or spacer produced simultaneously and sharing a common pitch with the respective paired features or spacers, and a second multiply patterned structure having a single right-hand feature or spacer produced simultaneously and sharing a common pitch with the respective paired features or spacers.

主权项

1. A multiply patterned metrology target, comprising:
at least two multiply patterned structures defined by respective pairs of features or pairs of spacers, which multiply patterned structures further comprise:
a first multiply patterned structure having a single left-hand feature or a single left-hand spacer produced simultaneously and sharing a first common pitch with the respective pairs of features or pairs of spacers; and,a second multiply patterned structure having a single right-hand feature or a single right-hand spacer produced simultaneously and sharing the first common pitch with the respective pairs of features or pairs of spacers.