Methods for the synthesis and purification of polycycloalkane candidates for photolithography immersion fluids at 193  nm: requirements for removal of oxygen

Juan Lopez Gejo; Joy T. Kunjappu; Willard E. Conley; Paul A. Zimmerman; Nicholas J. Turro

doi:10.1117/1.2778641

1 July 2007 Methods for the synthesis and purification of polycycloalkane candidates for photolithography immersion fluids at 193 nm: requirements for removal of oxygen

Juan Lopez Gejo, Joy T. Kunjappu, Willard E. Conley, Paul A. Zimmerman, Nicholas J. Turro

Author Affiliations +

Journal of Micro/Nanolithography, MEMS, and MOEMS, Vol. 6, Issue 3, 033003 (July 2007). https://doi.org/10.1117/1.2778641

Abstract

Cycloalkanes are candidates for immersion fluids because of their potential for low absorption in the 193-nm region and for a high refractive index (RI). We have developed an empirical correlation between refractive index and density of alkanes, which allows a prediction of the best candidates for immersion fluids based on the alkane structure. In particular, the correlation reveals that polycycloalkanes such as perhydrophenanthrene (PHPh) and perhydrodropyrene (PHPy), which have a higher RI than linear or cyclic alkanes, will be excellent candidates for immersion fluids at 193 nm. Therefore, PHPh and PHPy were synthesized by exhaustive hydrogenation of phenanthrene and pyrene. However, methods for the purification of the synthesized and commercial alkanes such as cyclodecane (CYD), cyclohexane (CYX), pentane (PNT), and decalin (DEC) are required in order to determine the actual absorption of candidates at 193 nm. The presence of an absorbing impurity at 193 nm can cause the premature elimination of otherwise excellent potential candidates. A rather subtle impurity is molecular oxygen, which does not itself absorb at 193 nm, but which forms complexes with alkanes that do absorb at 193 nm. In this case, the "impurity" is readily eliminated by simple purging with nitrogen or argon gas.

©(2007) Society of Photo-Optical Instrumentation Engineers (SPIE)

Citation Download Citation

Juan Lopez Gejo, Joy T. Kunjappu, Willard E. Conley, Paul A. Zimmerman, and Nicholas J. Turro "Methods for the synthesis and purification of polycycloalkane candidates for photolithography immersion fluids at 193 nm: requirements for removal of oxygen," Journal of Micro/Nanolithography, MEMS, and MOEMS 6(3), 033003 (1 July 2007). https://doi.org/10.1117/1.2778641

Published: 1 July 2007

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available