TANDON, Shakul,WALLACE, Charles H.,NYHUS, Paul A.,WEISS, Martin N.
申请号：
WO2015US67198
公开号：
WO2017111925(A1)
申请日:
2015.12.21
申请国别(地区):
世界知识产权组织国际局
年份:
2017
代理人:
摘要：
Multi-pitch or variable pitch grating structures for overlay, dose, or focus information extraction are described. In an example, a method of performing optical metrology of a semiconductor structure includes providing a semiconductor structure having an underlying layer comprising a pre-patterned grating structure having a pitch. The method also includes providing an overlying layer on the underlying layer, the overlying layer including a grating pattern having two or more pitches different from the pitch of the pre-patterned grating structure of the underlying layer. The method also includes measuring for a shift in overlay of the overlying layer relative to the pre-patterned grating structure of the underlying layer.
