Masaaki Takasuka

Development of new xanthendiol derivatives applied to the negative-tone molecular resists for EB/EUVL

In this paper, we report the development of new xanthendiol derivatives applied to the negative-tone molecular resists for EB/EUVL. The new xanthendiol derivatives were easily synthesized by the condensation of aldehydes and dihydroxyaromatic compounds. We found 13,13’-biphenyl-bis(13H-benzoxanthen-2,11-diol) was showed the good applicability to the raw material for the resist for EB/EUVL. The EB patterning result showed the resist containing xanthendiol derivative could resolve the 20 nm half-pitch pattern, and 15 nm half-pitch patterns were partially resolved.

Development of molecular resists based on Phenyl[4]calixarene for EBL

In this paper, we report current performance of the negative-tone molecular resists based on calix[4]resorcinarene (CRA) by Electron Beam Lithography (EBL). We have developed hydroxyphenyl calix[4]resorcinarenes (H-CRAs) designed hydroxy-groups outer to adhere patterns to wafers. Hydroxy groups help patterns adhere to wafers, to restrain collapse of patterns. Moreover, we additionally controlled hydrophobicity of H-CRA by the alkyl-groups (R), which make the sensitivity higher. The negative-tone resist based on these H-CRAs shows well-defined 25-50nm half-pitch patterns, and the increase in hydrophobicity of H-CRA by the alkyl-groups (R) made the high sensitivity. Furthermore, the optimization of these resist formulation improved sensitivity and LER.

Investigation of correlation with the octanol water partition coefficient and the sensitivity of negative-tone molecular resists

In this paper, we report the investigation of correlation with the octanol water partition coefficient and the sensitivity of negative-tone molecular resists based on calix[4]resorcinarene (CRA) by Electron Beam Lithography (EBL). The sensitivity of negative-tone molecular resists were higher as the value of the Octanol water partition coefficient got smaller. It was confirmed that the octanol water partition coefficient was useful to the guess of sensitivity of negativetone molecular resists. Furthermore, we have developed calix[4]resorcinarenes showing well-defined sub 20nm halfpitch patterns.