Characterizing Polymer bound PAG Type EUV Resist

Abstract

Blurs, swelling properties and lithographic performance for polymer bound PAG and polymer PAG blended type resists were studied. A Blur strongly depends on PAG size and the polymer bound PAG type resist reduces the Blur. The Blur for the polymer bound PAG type resist is smaller than that for ZEP (non CAR). The fact indicates that polymer bound PAG should reduce secondary electron diffusion. The polymer bound PAG type resist acquires very small Blur with higher sensitivity and suppresses swelling very well, therefore polymer bound PAG is one of the promising technologies that improve resolution, LWR and sensitivity (RLS) property. RLS property on EUV exposure tool is significantly improved by using the polymer bound PAG type resist. Resolution reaches 24 nmhp and is limited by pattern collapse and line breaking. Further lithographic experiments on EB exposure tool which has higher NILS than EUV exposure tool are carried out in order to make clear relation between Blur and resolution. The resolution of the polymer bound PAG type resist reaches 17.5 nmhp with 35 nm thickness and there is possibility that the resolution of an optimized polymer bound PAG type resist reaches under 15 nmhp. The resolution of the resist with lower capillary force (C.F.) given and lower swelling and on higher NILS exposure tool strongly depends on the Blur.

Resist material options for extreme ultraviolet lithography

“…The segregation of acid generators to the interfaces [34] and the inhomogeneous distribution of acid generators due to the aggregation are also problems. A polymer, to which the acid generators are bound through a covalent bond, is being developed to circumvent these problems [35][36][37].…”

A chemically amplified molecular glass resist with an ionic photoacid generator and a single protection group

“…Also, the reduction in the diffusion length of the photo‐generated acid is known as a way to improve the LER, because a low acid diffusion length leads to an increase in the image contrast, and the resolution and LER can then be improved . Therefore, many approaches for reducing the acid diffusion length have been developed, such as ionic PAGs with large‐sized anion moieties, PAG bound polymer photoresists and PAG bound molecular glass resists …”

Dissolution Kinetics in Polymer-Bound and Polymer-Blended Photo-Acid Generators

“…Many attempts to incorporate acid generators such as ionic and non-ionic PAGs into backbone or pendant groups of polymers have been reported mainly to circumvent the problem related to compatibility of acid generators or to suppress acid diffusion in resist matrices. [16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34] It is very important to know whether a polymer bound PAG provides a substantial advantage over polymer blended PAG in terms of resolution, sensitivity, LWR tradeoffs. Up to now, it is known that the polarity and hydrophobicity of the polymer were very different from those of the polymer when the acid generators were incorporated into polymers.…”