In order to improve EUVL resist characteristics, especially sensitivity, we have investigated two types of partially fluorinated resist polymers. The one was side chain fluorinated PHS type resist polymers. The other was main chain fluorinated resist polymers. Poly (p-hydroxystyrene) (PHS) type polymers with trifluorostyrene (TFSt) were synthesized and characterized their sensitivity behavior. From this evaluation, we found that PHS contained TFSt unit had a high sensitivity, keeping their etching durability. We expect that TFSt unit can work to enhance the resist sensitivity in PHS based EUVL resist polymers. Main chain fluorinated polymers based FIT unit (FITMAd and FITAdOM) were synthesized. FITMAd and FITAdOM showed high sensitivity compared to non fluorinated reference sample. From molecular weight measurement, we infer that the polymer main chain of FITMAd can be decomposed by irradiating with EUV light. The outgassing of FITMAd and FITAdoM were measured. There is no big difference between the total outgassing of FIT polymers and that of non fluorinated acrylic sample. And small amount of Hydrogen fluoride (HF) were detected. We infer that FITMAd and FITAdOM are decomposed then HF is generated under EUV exposure. From these results, we expect that FIT unit can work to enhance the resist sensitivity and can act main chain decomposed resist unit in EUVL resist polymers.

Date Published: 26 March 2008
PDF: 7 pages
Proc. SPIE 6923, Advances in Resist Materials and Processing Technology XXV, 692347 (26 March 2008); doi: 10.1117/12.772542

Published in SPIE Proceedings Vol. 6923:
Advances in Resist Materials and Processing Technology XXV
Clifford L. Henderson, Editor(s)