28P L/S Dry Resist Process Flow Co-optimization at Low NA EUV

The all dry deposited and dry developed negative tone metal-oxide dry resist by Lam Research has demonstrated many advantages such as high EUV sensitivity, improved resolution and low stochastic defectivity. In this work, we report the dry resist process insertion to a Cu damascene test vehicle flow to create a 28nm pitch line-space (L/S) pattern. Electrically testable 1cm and 1m Comb-Serp monitor structures were evaluated to validate the dry resist performance. We showcase that with dry resist technology, we can achieve > 90% yield in 1m comp-serp macro for 28nm pitch L/S structure on a single EUV dose wafer. With the dry resist process co-optimization, we can improve both the dose to size (DtS) and LER/LWR at after development inspection (ADI) process. In addition, process window of electrical test can also be modulated and improved without compromising dose to size. This work can support the industry in recognizing the unique advantages of single patterning at 0.33NA using dry resist and thereby broadening its adoption as a competitive solution to the known complexities of double patterning.