Patterning Aware Design Optimization of Selective Etching in N5 and Beyond

The aggressive scaling towards N5 causes the difficulty in controlling process variations for line and block (cut) printing, while the margin for edge placement errors (EPE) is decreasing. Selective etching, implemented by self-aligned multiple patterning with alternating materials, introduces better EPE margins with self-aligned blocks (SAB). In this paper, we propose a systematic study on design space for SAB with various options of design rules. We also develop a post SAB optimization framework to evaluate the impacts of different rules. Based on the experiments on 6-track industrial benchmarks, we explore possible options for closure of current physical design flow.