Patent ID: 10832945

Abstract:
Techniques to improve CD width and depth uniformity between features with different layout densities are provided. In one aspect, a method of forming a contact structure includes: patterning features in different regions of a dielectric at different layout densities whereby, due to etch loading effects, the features are patterned to different depths in the dielectric and have different bottom dimensions; depositing a sacrificial spacer into/lining the features whereby some of the features are pinched-off by the sacrificial spacer; opening up the sacrificial spacer at bottoms of one or more of the features that are not pinched-off by the sacrificial spacer; selectively extending the one or more features in the dielectric, such that the one or more features have a discontinuous taper with a stepped sidewall profile; removing the sacrificial spacer; and filling the features with a conductive material to form the contact structure. A contact structure is also provided.