Fluoropolymers for 157/193 nm Lithography: Chemistry, New Platform, Formulation Strategy, and Lithographic Evaluation.

Itô, Hiroshi; Truong, Hoa D.; Okazaki, Masaki; Miller, Dolores C.; Fender, Nicolette; Brock, Phillip J.; Wallraff, G. M.; Larson, Carl E.; Allen, Robert D.

doi:10.2494/photopolymer.15.591

Cited by 28 publications

(7 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…57 We synthesized a variety of new trifluoromethacrylates bearing polyfluoroalkyl ester moieties, 58,59 which would serve as monomers for potential photoresists and as a component of optical fibers. Although we did not follow up this line of research in my laboratory, TFMA esters have been extensively studied and are still under active investigation for the development of photoresists for lithography using short wave length light, e.g., 157/193 nm, 60–62 as we envisioned in 1980s. 24,58 …”

Section: Carbonylations Of α-(Trifluoromethyl)vinyl Bromidementioning

confidence: 99%

Exploration of Fluorine Chemistry at the Multidisciplinary Interface of Chemistry and Biology

Ojima

2013

J. Org. Chem.

175

View full text Add to dashboard Cite

Over the last three decades, my engagement in “fluorine chemistry” has evolved substantially, because of the multidisciplinary nature of the research programs. I began my research career as a synthetic chemist in organometallic chemistry and homogeneous catalysis directed toward organic synthesis. Then, I was brought into a very unique world of “fluorine chemistry” in the end of 1970s. I started exploring the interface of fluorine chemistry and transition metal homogeneous catalysis first, which was followed by amino acids, peptides, and peptidomimetics for medicinal chemistry. Since then, I have been exploring the interfaces of fluorine chemistry and multidisciplinary fields of research involving medicinal chemistry, chemical biology, cancer biology and molecular imaging. This perspective intends to cover my fruitful endeavor in the exploration of fluorine chemistry at the multidisciplinary interface of chemistry and biology in a chronological order to show the evolution of my research interest and strategy.

show abstract

Section: Carbonylations Of α-(Trifluoromethyl)vinyl Bromidementioning

confidence: 99%

Exploration of Fluorine Chemistry at the Multidisciplinary Interface of Chemistry and Biology

Ojima

2013

J. Org. Chem.

175

View full text Add to dashboard Cite

show abstract

“…6-9 Figure 1 shows the structures of several vinyl ether monomers that have been copolymerized with tert-butyl trifluoromethacrylate by Ito and coworkers. 9 Herein, we discuss initial attempts at preparing trifluoromethacrylate-vinyl ether copolymers. Simple copolymerizations with a trifluoromethacrylate (TFMA-1) and vinyl ether (VE-1) generate high molecular weight polymer under common polymerization conditions (i.e., neat to 50 weight percent solids, approximately 10 mole percent initiator, and temperatures between 60 and 80 °C), but a typical molecular weight target for methacrylate photoresist polymers is Mw < 20,000 g/mol.…”

Section: Resultsmentioning

confidence: 99%

High absorbing resists based on trifluoromethacrylate-vinyl ether copolymers for EUV lithography

Christianson

Meyer

Ongayi³

et al. 2013

SPIE Proceedings

View full text Add to dashboard Cite

Highly sensitive EUV photoresists remain a critical challenge to enable high volume manufacturing with EUV lithography. Chemically amplified resists continue to provide the best sensitivity for EUV photoresists, but the high EUV transparency of most resists continues to waste a large percentage of EUV photons that pass through the resist film without photochemically generating acid. Highly fluorinated polymers have been proposed as more sensitive resist materials because fluorine increases EUV absorption of a material. Thus, methacrylate-like polymers with fluorinated backbones are an attractive possibility for new EUV resist materials.Trifluoromethacrylates are known to undergo free radical polymerization with electron rich comonomers such as vinyl ethers. The resulting polymers have backbone trifluoromethyl groups that enhance the absorption of EUV photons while retaining the potential for solubility change by acid-catalyzed tertiary ester deprotection similar to methacrylate-based chemically amplified resists. Interestingly, copolymerizations of trifluoromethacrylates and vinyl ethers are not particularly sensitive to traditional experimental parameters that influence polymer molecular weight. Instead, we have found that the structure of the vinyl ether comonomer has a profound impact on polymer molecular weight with acyclic vinyl ethers generating very high molecular weight polymers (Mw exceeding 100,000 g/mol) and cyclic vinyl ethers generating very low molecular weight polymers (Mw less than 10,000 g/mol) under similar conditions. Combination of cyclic and non-cyclic vinyl ethers in the monomer feed enables the synthesis of polymers at a desired molecular weight with a narrow polydispersity (PDI less than 2). Initial EUV contrast curves demonstrate potential for highly sensitive photoresists using these backbone-fluorinated polymers.A variety of polymers have been prepared to determine optimum compositions of leaving group, sensitizing, and etch resistant monomers. Additionally, compositions with a variety of functional groups were prepared to optimize the polymer properties to enable resists that form uniform films with low unexposed film thickness loss while maintaining high EUV sensitivity. EUV lithography of one of the resist materials demonstrates its utility as a photoresist capable of printing features to about 30 nm. Continued optimization of materials is focused on resolving features below 20 nm.

show abstract

“…Figure 2 summarizes the results. The film thickness is not a function of bake temperature above 120 °C, as expected from the low residual PGMEA concentration of 0.4 wt% detected in a PNBHFA baked at 130 °C for 60 sec 15 (4 wt% in PHOST under the same conditions 16 ). However, the dissolution rate is influenced by the initial film thickness, more in the case of a lower bake temperature.…”

Section: Dissolution Kinetics Of Pnbhfamentioning

confidence: 86%

Hydrogen bonding and aqueous base dissolution behavior of hexafluoroisopropanol-bearing polymers

Itô

Hinsberg

Rhodes

et al. 2003

Advances in Resist Technology and Processing XX

View full text Add to dashboard Cite

The aqueous base dissolution behavior and hydrogen bonding interaction of polymers bearing hexafluoroisopropanol (HFA) as an acid group have been investigated. While pKa of HFA is similar to that of phenol, the dissolution rate of HFA polymers in aqueous base varies from one structure to another. Poly(norbornene hexafluoroisopropanol) (PNBHFA) dissolves in 0.26 tetramethylammonium hydroxide (TMAH) aqueous solution at a rate of 1,500-8,000 A/sec, which is not correlated to the number-average or weight-average molecular weight. Furthermore, PNBHFA exhibits a complex multi-stage dissolution kinetics in 0.21 N TMAH, depending on the molecular weight and molecular weight distribution. Hydrogen bonding of HFA polymers has been investigated using FTIR. Polynorbornene and polystyrene bearing HFA (PNBHFA and PSTHFA) are much less hydrogen-bonded than poly(4-hydroxystyrene) (PHOST). HFAester copolymers tend to have more free OH groups than a HOST/t-butyl acrylate copolymer. The carbonyl bond in 2-trifluoromethylacrylic units is less polarized and therefore less prone to hydrogen bonding with OH than C=O in (meth)acrylate units. The interaction of acid generators with the HFA group can be studied by 19 F NMR. Both ionic iodonium and nonionic imidesulfonate acid generators interact strongly with HFA and inhibit the dissolution of HFA polymers in aqueous base while ionic acid generators are better dissolution inhibitors of phenolic resins.

show abstract

Fluoropolymers for 157/193 nm Lithography: Chemistry, New Platform, Formulation Strategy, and Lithographic Evaluation.

Cited by 28 publications

References 14 publications

Exploration of Fluorine Chemistry at the Multidisciplinary Interface of Chemistry and Biology

Exploration of Fluorine Chemistry at the Multidisciplinary Interface of Chemistry and Biology

High absorbing resists based on trifluoromethacrylate-vinyl ether copolymers for EUV lithography

Hydrogen bonding and aqueous base dissolution behavior of hexafluoroisopropanol-bearing polymers

Contact Info

Product

Resources

About