Simultaneous via and trench patterning using different etch rates

One embodiment of the present invention relates to a photolithography mask configured to form a metallization and via level utilizing a single lithography and etch process. More particularly, a photolithography mask comprising a mask via shape and one or more metal wire shapes is configured to produce both on-wafer metal lines and via levels. The mask via shape corresponds to an on-wafer photoresist via opening having a first critical dimension (CD). The one or more mask wire shapes correspond to one or more on-wafer photoresist wire openings respectively having a second CD. The first CD is larger than the second CD thereby providing a greater vertical etch rate for ILD exposed by the photoresist via opening than for ILD exposed by the one or more photoresist wire openings. This difference in CD results in a via extending vertically below the metal wire level, thereby making physical contact with underlying metal.