Plasma etch solutions for EUV patterning: defect challenges

EUV exposure stochastics remains a key limiter in driving lower dose and better economics for scaling EUV patterning implementation. In particular, the stochastics translates to resist defects that become detrimental to device performance and yield. There has been development and innovation in plasma etch to mitigate these defects during the pattern transfer process – key challenge to achieve high selectivity to EUV resist mask while etching the patterning layers. Advanced pulsing solutions as well as deposition-based approaches have been characterized and developed. This paper will delineate the various approaches, including the benefits and risks associated with each, in relation to the plasma etch requirements needed for the pattern transfer for current and future process nodes.