Strategies for Single Patterning of Contacts for 32nm and 28nm Technology

As 193 nm immersion lithography is extended indefinitely to sustain technology roadmaps, there is increasing pressure to contain escalating lithography costs by identifying patterning solutions that can minimize the use of multiple-pass processes. Contact patterning for the 32/28 nm technology nodes has been greatly facilitated by just-in-time introduction of new process enablers that allow the support of flexible foundry-oriented ground rules alongside high-performance technology, without inhibiting migration to a single-pass patterning process. The incorporation of device based performance metrics along with rigorous patterning and structural variability studies were critical in the evaluation of material innovation for improved resolution and CD shrink. Additionally novel design changes for single patterning along new capability in data preparation were both assessed to leverage minimal impact of implementation of a single patterning contact process into the existing 32nm and 28nm technology programs [1].