Dissolution kinetics in chemically amplified EUV resist

Polymer structure effects on the dissolution kinetics and deprotection reaction were investigated to understand inherent extreme ultraviolet (EUV) resist characteristics. The effect of protecting groups and protecting ratio on activation energy were observed. Also, the protecting ratio effect on dissolution kinetics was observed. The speed of TMAH penetration into each resist film was different for each resist as the concept of the "penetration zone". This indicated that the dominant rate-determining step in resists is TMAH penetration into the resist film. Thus, the dissolution rates were affected by changing the protection ratio of polymer. Moreover, 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. It is important for EUV lithography to select appropriate protecting group and protecting ratio.