Resists for ArF

Remarkably, regardless of the resist technology approach used, it should be mentioned that the imaging mechanisms of resists for ArF lithography use... 

The third platform of resists for ArF lithography is the ester-protected acrylate/ah-cyclic polymer hybrid platform (XLII), which was pioneered at BeU labs. The polymerization route to polymers of this platform is free radical copolymerization... 

Chemically amplified Si-contained resist using silsesquioxane for ArF... 

A copolymer approach can provide more flexibility to the resist design because all the necessary functions do not have to reside on one component. Today s advanced positive deep UV resists are exclusively based on this concept with 4-hydroxystyrene as one component. However, early copolymer systems and some of the 193-nm resists consisted of lipophilic components only. Incorporation of 4-acetoxystyrene to poly(4- er -butoxycarbonyloxystyrene sulfone) has already been mentioned. This section deals with copolymer resists composed of lipophilic comonomers first and then the currently dominant hydroxystyrene copolymers. Co- and terpolymers for ArF excimer laser lithography will be described in a separate section. 

Kaimoto, K. Nozaki, S. Takechi, andN. Abe, Alicyclic polymer for ArF and KrF excimer resist based on chemical amplification, Proc. SPIE 1672, 66 (1992). 

The second platform of ester-protected positive resists designed for ArF lithography is the alicyclic polymer platform,which was first developed at the University of Texas at Austin,and involves resists in which the alicyclic units with pendant ester-protecting groups, acidic groups, and adhesion-promoting groups constitute the backbone of the polymer. Resist polymers of this platform... 

Scheme 7.38 Free radical copolymerization of various alicyclic monomers initiated by (1) azoisobutyronitrile (AIBN) in THF, and (2) di-tert-butyl peroxide (DTBP) in propylene glycol monomethylether acetate, and used in the synthesis of the alicyclic polymer resist materials for ArF lithography, pioneered at the University of Texas at Austin in 1995. Note that although only 2,3-enchainment of the cyclic olefins is shown above the scheme, 2,7-enchainement is also possible, as reported by Gaylord and co-workers. ...

Promising positive-tone bilayer resists based on silicon-containing methacrylate polymers bearing acid labile side groups (Scheme 7.49), and designed for ArF lithography, were reported in 1996 by researchers at Olin Ceiba-Geigy... 

The methodologies reported here follow from U. Okoroanyanwu, J.D. Byers, T. Cao, S.E. Webber, and C.G. Willson, Deprotection kinetics of alicyclic polymer resist systems designed for ArF (193 nm) lithography, in Polymers for Micro and Nano Patterning Science and Technology, H. Itoh, E. Reichmanis, O. Nalamasu, and T. Ueno, Eds., pp. 174 190, American Chemical Society, Washington, DC (1998). 

Deprotection Kinetics of Alicyclic Polymer Resist Systems Designed for ArF (193 nm) Lithography... 

EUV Resists Certain polymer formulations of the types used for KrF and ArF photolithography are capable also of serving as EUV resists (for chemical structures, see Sections 3.3.3.2 and 3.3.3.3) [130]. This pertains, for instance, to copolymers containing alicydic groups and fluorine atoms (Chart 5.15). 

In conclusion, we have shown that successful treatment of MI and I/R AKI with MSC holds substantial promise for the development of novel, MSC-based interventions that can improve the treatment of severe, and still largely therapy-resistant, clinical ischemic myocardial infarction as well as ARF that results from I/R injury. Pluripotent MSC, because of their versatility and the ease with which they can be harvested from the bone marrow, culture expanded, and engineered, appear to be a particularly well-suited stem cell type for these clinical indications. 

The mixture was initially filtered through a 0.2 pm pore diameter teflon filter. It was spin-coated onto a silicon wafer previously sprayed with hexamethyldisilazane and baked for 40 seconds at 90°C and 90 seconds at 110°C, forming a 500 nm resist film. The resist film was exposed to ArF excimer laser light, heat treated for 90 seconds at 110°C, and cooled to ambient temperature. It was then dipped in 2.38% aqueous tetramethylammonium hydroxide solution for 60 seconds for development where it formed a 1 1 line-and-space pattern. The wafer as developed was... 

Chemical amplification type positive resist compositions provided in Table 1 were prepared by Takemoto [4] and were suitable for excimer laser lithography using ArF and KrF lasers. 

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