PMMA removal selectivity to PS using dry etch approach: sub-10nm patterning application

Block copolymer selectivity: A new dry etch approach for cylindrical applications

“…This result is in good agreement with a previous study showing an increase in the CD after CO-H 2 chemistry as a function of the process time. 15 In the meantime, these cross-section views confirm a low PMMA consumption and no PS etch with the 15 s-CO step as already observed on blanket wafers, while 30 nm of PMMA and 10 nm of PS are removed with the 25 s-CO-H 2 step.…”

“…To have a better understanding, we have compared XPS analysis obtained for the cycling chemistry with results obtained for CO and CO-H 2 chemistry which have been previously presented in detail. 15 PS and PMMA surface compositions for CO and CO-H 2 processes have been plotted in Fig. 4.…”

“…These mechanisms have been deeply detailed in the previous paper. 15 The evolution of PS and PMMA surface compositions during CO and CO-H 2 cycling chemistry has been plotted in Fig. 5.…”