Development of Nickel-Based Negative Tone Metal Oxide Cluster Resists for Sub-10 nm Electron Beam and Helium Ion Beam Lithography.

Hybrid metal-organic cluster resist materials, also termed as organo-inorganics, demonstrate their potential for use in next-generation lithography owing to their ability for patterning down to ∼10 nm or below. High-resolution resist patterning is integrally associated with the compatibility of the resist and irradiation of the exposure source. Helium ion beam lithography (HIBL) is an emerging approach for the realization of sub-10 nm patterns at considerably lower line edge/width roughness (LER/LWR) and higher sensitivity as compared to electron beam lithography (EBL).

Correction: EUV photofragmentation study of hybrid nonchemically amplified resists containing antimony as an absorption enhancer.

[This corrects the article DOI: 10.1039/C7RA12934C.].

Engineering Multifunctionality in Hybrid Polyoxometalates: Aromatic Sulfonium Octamolybdates as Excellent Photochromic Materials and Self-Separating Catalysts for Epoxidation.

Engineering multifunctionality in hybrid polyoxometalates (hybrid POMs) is an interesting but scarcely explored topic. Herein, we set about engineering two important materials properties, viz., photochromism and self-separating catalysis, in a hybrid POM by modulating the counterion motif.

Polyarylenesulfonium Salt as a Novel and Versatile Nonchemically Amplified Negative Tone Photoresist for High-Resolution Extreme Ultraviolet Lithography Applications.

The present report demonstrates the potential of a polyarylenesulfonium polymer, poly[methyl(4-(phenylthio)-phenyl)sulfoniumtrifluoromethanesulfonate] (PAS), as a versatile nonchemically amplified negative tone photoresist for next-generation lithography (NGL) applications starting from i-line (λ ∼ 365 nm) to extreme ultraviolet (EUV, λ ∼ 13.5 nm) lithography. PAS exhibited considerable contrast (γ), 0.

Patterning highly ordered arrays of complex nanofeatures through EUV directed polarity switching of non chemically amplified photoresist.

Given the importance of complex nanofeatures in the filed of micro-/nanoelectronics particularly in the area of high-density magnetic recording, photonic crystals, information storage, micro-lens arrays, tissue engineering and catalysis, the present work demonstrates the development of new methodology for patterning complex nanofeatures using a recently developed non-chemically amplified photoresist (n-CARs) poly(4-(methacryloyloxy)phenyl)dimethylsulfoniumtriflate) (polyMAPDST) with the help of extreme ultraviolet lithography (EUVL) as patterning tool. The photosensitivity of polyMAPDST is mainly due to the presence of radiation sensitive trifluoromethanesulfonate unit (triflate group) which undergoes photodegradation upon exposure with EUV photons, and thus brings in polarity change in the polymer structure. Integration of such radiation sensitive unit into polymer network avoids the need of chemical amplification which is otherwise needed for polarity switching in the case of chemically amplified photoresists (CARs).

Aromatic Sulfonium Polyoxomolybdates: Solid-State Photochromic Materials with Tunable Properties.

A new aromatic sulfonium counter-ion motif for polyoxometalate (POM) clusters with potential for structural and electronic fine-tuning has been designed. Its two derivatives 4-hydroxyphenyl dimethylsulfonium triflate (HPDST) and 4-(allyloxy)phenyl dimethylsulfonium triflate (APDST) exhibit ionic liquid behaviors under ambient conditions. HPDST and APDST are used to develop a series of aromatic sulfonium POM hybrids (HPDS/APDS)n[XMo12 O40] (HPDS and APDS are the cations of HPDST and APDST, respectively; X=P or Si; n=3 or 4), which are tested for photochromic behavior.

Selective Fragmentation of Radiation-Sensitive Novel Polymeric Resist Materials by Inner-Shell Irradiation.

Two key concepts in extreme ultraviolet lithography (EUVL) are important for it to be a candidate for the mass production of future integrated circuits: the polymer formulation and the photofragmentation process. In this work, both concepts were carefully studied. The design and synthesis of radiation-sensitive organic polymeric materials based on the inclusion of a radiation-sensitive tetrahydrothiophenium functional group are outlined.

New polyoxometalates containing hybrid polymers and their potential for nano-patterning.

Two new polyoxometalate (POM)-based hybrid monomers (Bu4 N)5 (H)[P2 V3 W15 O59 {(OCH2 )3 CNHCO(CH3 )CCH2 }] (2) and (S(CH3 )2 C6 H4 OCOC(CH3 )=CH2 )6 [PV  2Mo10 O40 ] (5) were developed by grafting polymerizable organic units covalently or electrostatically onto Wells-Dawson and Keggin-type clusters and were characterized by analytical and spectroscopic techniques including ESI-MS and/or single-crystal X-ray diffraction analyses. Radical initiated polymerization of 2 and 5 with organic monomers (methacryloyloxy)phenyldimethylsulfonium triflate (MAPDST) and/or methylmethacrylate (MMA) yielded a new series of POM/polymer hybrids that were characterized by (1) H, (31) P NMR and IR spectroscopic techniques, gel-permeation chromatography as well as thermal analyses. Preliminary tests were conducted on these POM/polymer hybrids to evaluate their properties as photoresists using electron beam (E-beam)/extreme ultraviolet (EUV) lithographic techniques.

Radiation-sensitive novel polymeric resist materials: iterative synthesis and their EUV fragmentation studies.

Polymerization of (4-(methacryloyloxy)phenyl)dimethylsulfoniumtriflate (MAPDST), as a key monomer containing the radiation sensitive sulfonium functionality, with various other monomers such as methyl methacrylate (MMA), 4-carboxy styrene (STYCOOH), N-vinyl carbazole (NVK) in different molar ratios via free-radical polymerization method is described. This methodology led to the development of a small chemical library of six different radiation sensitive polymers for lithography applications. Fourier transform infrared (FT-IR) and nuclear magnetic resonance (NMR) spectroscopy identified the reaction products as MAPDST homopolymer and MAPDST-MMA, MAPDST-STYCOOH, MAPDST-NVK copolymers.

Nafcillin-loaded PLGA nanoparticles for treatment of osteomyelitis.

The goal of this investigation is to develop poly(DL-lactide-co-glycolide) (PLGA) nanoparticles for the delivery of antibiotics such as nafcillin to osteoblasts. This is important in order to treat Staphylococcus aureus-mediated osteomyelitis. The latter is often chronic and highly resistant to antibiotics.

Design and performance of EUV resist containing photoacid generator for sub-100 nm lithography.

To fulfill the SIA roadmap requirements for EUV resists, the development of entirely new polymer platforms is necessary. In order to address issues like Line Edge Roughness (LER) and photospeed, we have developed a novel chemically amplified photoresist containing a photoacid generator (PAG) in the main chain of the polymer. The incorporation of a cationic PAG unit, phenyl methacrylate dimethylsulfonium nonaflate (PAG), in the resist backbone showed increased sensitivity, when compared with analogous blend PAG resist samples.

Lithography application of a novel photoresist for patterning of cells.

Photolithography is the current workhorse for the microelectronic industry. It has been used extensively for the creation of patterns on two-dimensional surfaces. Various research groups have studied the use of photolithography to pattern surfaces for the alignment of cells.

Synthesis, characterization, and preliminary biological study of poly(3-(tert-butoxycarbonyl)-N-vinyl-2-pyrrolidone).

Poly(3-(tert-butoxycarbonyl)-N-vinyl-2-pyrrolidone) has been synthesized and characterized by gel permeation chromatography, Fourier transform infrared spectroscopy, NMR spectroscopy, and thermal analysis. The polymer is a chemically amplified photoresist. Arrays of lines with 25 microm width and 25 microm spacing were successfully patterned with this polymer by photolithography.