Voltage contrast determination of design rules at the limits of EUV single patterning

Abstract

We have used large-field-of-view voltage contrast metrology to determine the design rules on a pitch 28 nm single-exposure extreme ultra violet dual damascene process, and to study a use case in which two design parameters, metal tip-to-tip critical dimension and via-to-line placement, interact nontrivially in the yield determination. By designing proper test structures, it is possible to determine the different failure mechanisms for the given process integration and determine the patterning cliffs and design rules.