Cut-Process Overlay Yield Model for Self-aligned Multiple Patterning and a Misalignment Correction Technique Based on Dry Etching

In this paper, we present a cut-process overlay yield model for self-aligned multiple patterning and study how its yield will be affected by the overlay errors and cut-hole overhang. A geometric model is developed to identify the yield-related structures and construct the probability-of-failure (POF) functions. A general formula to calculate the cut-process overlay yield is derived using the joint POF function. Our calculation results show that an optimal cut-hole overhang must be found in order to achieve the maximum yield. The scaling tendency of the cut-process overlay yield is also studied, and it is found to be a potential challenge when the half pitch of device features reaches 7nm. The yields of 4-mask 193i and single-mask EUV cut modules are also calculated for a comparison. Moreover, a post-lithography misalignment correction technique based on dry etching is proposed. A geometric tilted etching model is developed to predict the relation between the tilting angle of an etching process and the shifted distance of the etched structure's mass center.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000322989800014&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Engineering, Electrical & ElectronicNanoscience & NanotechnologyOpticsEICPCI-S(ISTP)