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

Abstract

In the fabrication beyond 16 nm node, the uniform distribution of acid generators in resist matrix is a serious concern. Recently, the incorporation of acid generators to polymers via covalent bonds has attracted much attention in order to overcome the compatibility problem of acid generators with polymers and reduce the diffusion lengths of acid, which leads to high resolution and low line edge roughness (LER). However, understanding of the resist dissolution kinetics in polymer-bounded and polymer-blended photo-acid generator (PAG) for extreme ultraviolet (EUV) lithography is insufficient. Therefore, it is significantly important to clarify the effect of binding acid generator with polymer on the dissolution kinetics. In this study, dissolution kinetics in polymer-bound and polymer-blended PAG was investigated to understand inherent EUV resist characteristics. The development rate R(E,Z) at different depth position in resist film was determined in polymer-bounded and polymer-blended PAG using resist development analyzer (RDA-800EUV) measurement system. The difference of R(E,Z) in polymer-bounded and polymer-blended PAG was observed. Also, the preliminary evaluation of resist profile for EUV chemically amplified resists was performed by using PROLITH and parameters obtained with EUV exposure tool. Furthermore, the resist patterns were produced by electron beam and the SEM observation results were compared with the PROLITH simulation results.

Affinity Analysis of Photoacid Generator in the Thin Film of Chemical Amplification Resist by Contact Angle Measurement

“…On the other hands, the bound resist is not a mixture, because the PAG unit is contained in the base polymer. The difference of the blend and bound resists has been reported by many researchers [10][11][12][13][14][15][16][17][18], and especially, Watanabe et al have reported that the bound resist is more less line edge roughness (LER) than blend resist [11]. The reason of low LER for bound resist is expected that the uniformity of bound resist is better than blend one, however, the chemical composition distribution analysis has not been evaluated.…”

Study of Interrelation Between Reaction of Polymer-Bound/Blend Photoacid Generator with Solvated Electron and Acid Generation Efficiency

“…[3][4][5][6][7][8][9] In particular, polymer-bound photoacid generators (PAGs) (anion bound) are actively investigated as EUV resists. [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24] Many experimental results have shown that polymerbound PAGs have higher resolution than conventional resists (polymer-blend PAGs). On the other hand, the sensitivities of polymer-bound PAGs (anion bound) and polymer-blend PAGs are almost the same.…”