JSR (Japan)

We introduce thin underlayer (UL) materials (<10 nm) for metal oxide resist (MOR) that can support the lithography performance requirements as well as compatible with conventional etching tool and etching process. Thin UL materials for MOR patterning applications required to have chemical moieties with specific functions and excellent physical properties to meet both lithography and etching performance requirements. We investigated the relationship between surface properties of thin UL materials and its effects on MOR sensitivity, pattern collapse, and defects. We also discussed plausible mechanism based on our experimental results. In addition, we have also confirmed the impact of high EUV absorption unit effect in UL materials on MOR sensitivity.

Thiol-reactive reagents designed for the chemical modification of proteins cannot, in general, be used directly for the modification of intracellular targets because the presence of millimolar concentrations of glutathione inside cells effectively outcompetes reaction with target thiols. Here we report an equilibrium, entropic strategy for achieving target selectivity using a cyanoacrylate-based thiol-reactive cross-linker (BCNA) with two reactive sites. This compound exhibits ≳200-fold selectivity for reaction with target peptides and proteins containing appropriately spaced pairs of thiols, versus reaction with mono-thiols. Photo-isomerization of the azobenzene moiety of the cross-linker can be used to affect the conformation of the target peptide or protein. This approach suggests a general strategy for the chemical modification of intracellular peptide and protein targets.

Over-thousand-nanometer (OTN) near-infrared (NIR) fluorophores are useful for biological deep imaging because of the reduced absorption and scattering of OTN-NIR light in biological tissues. IR-1061, an OTN-NIR fluorescent dye, has a hydrophobic and cationic backbone in its molecular structure, and a non-polar counter ion, BF4−. Because of its hydrophobicity, IR-1061 needs to be encapsulated in a hydrophobic microenvironment, such as a hydrophobic core of polymer micelles, shielded with a hydrophilic shell for bioimaging applications. Previous studies have shown that the affinity of dyes with hydrophobic core polymers is dependent on the polarity of the core polymer, and that this characteristic is important for designing dye-encapsulated micelles to be used in bioimaging. In this study, the dye–polymer affinity was investigated using hydrophobic polymer films with different chiral structures of poly(lactic acid). IR-1061 showed higher affinity for l- and d-lactic acid copolymers (i.e., poly(dl-lactic acid) (PDLLA)) than to poly(l-lactic acid) (PLLA), as IR-1061 shows less dimerization in PDLLA than in PLLA. In contrast, the stability of IR-1061 in PDLLA was less than that in PLLA due to the influence of hydroxyl groups. Choosing hydrophobic core polymers for their robustness and dye affinity is an effective strategy to prepare OTN-NIR fluorescent probes for in vivo deep imaging.

ABSTRACTThis article presents the effect of some ionic photochemical acid generators (PAGs) to inhibit the dissolution of hexafluoroisopropylalcohol (HFA)‐containing polystyrene to an aqueous alkaline developer, which is a highly important effect in photoresist application to enhance resolution of patterning. The dissolution inhibiting factors and mechanisms were investigated by evaluating the solubility and the 1H‐NMR analysis of OH proton in HFA moiety. The dissolution inhibition effect was enhanced when the structures of PAGs fulfill some requirements: (a) their anions should have higher basicity and smaller van der Waals volume; (b) their cations should be stabilized by conjugation with electron‐rich aromatics. In the dissolution inhibition, the HFA moiety interacts with the anionic part of PAGs liberated from the electrostatic interaction with the counter cation. These interactions were predicted and quantified by DFT calculations using Gaussian 09, leading to the rational designs of PAGs with higher dissolution inhibiting effect in photoresist systems. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 531–538

This paper describes the synthesis and characterization of a class of highly stretchable and degradable semiconducting polymers. These materials are multi-block copolymers (BCPs) in which the semiconducting blocks are based on the diketopyrrolopyrrole (DPP) unit flanked by furan rings and the insulating blocks are poly(ε-caprolactone) (PCL). The combination of stiff conjugated segments with flexible aliphatic polyesters produces materials that can be stretched >100%. Remarkably, BCPs containing up to 90 wt% of insulating PCL have the same field-effect mobility as the pure semiconductor. Spectroscopic (ultraviolet-visible absorption) and morphological (atomic force microscopic) evidence suggests that the semiconducting blocks form aggregated and percolated structures with increasing content of the insulating PCL. Both PDPP and PCL segments in the BCPs degrade under simulated physiological conditions. Such materials could find use in wearable, implantable, and disposable electronic devices.

This paper presents the latest lithographic advances to enable scaling of packaging redistribution layer (RDL) feature size towards 1-2 μm line and space on panel-based glass substrates. Critical dimension (CD) of 1 μm line and space with aspect ratio (AR) of 5 was demonstrated in a newly developed chemically amplified plating photoresist by using i-line contact mask aligners and low numerical aperture (NA) 1x projection steppers. The minimum line and space demonstrated was 0.9 μm with AR of 5.5. Such high AR package RDL has much lower trace resistance compared to silicon back-end-of-line (BEOL) RDL, enabling power-efficient higher bandwidth. The relationship between resolution (R) and depth-of-focus (DOF) for low NA projection stepper is discussed. Low cost, low NA, large field steppers are better suited to large panel and large size package fabrication. A cost-effective mechanical fly-cut process was implemented for planarization of the entire wafer or panel with <; 1 μm flatness that ensures the success of 1 μm with AR of 5 lithography by using low cost lithographic tools.

EUV lithography is nowadays considered as one of the most feasible choices for high volume manufacturing. In this work, we wish to report a series of studies aiming at shedding more light on the development mechanism of metal based EUV hybrid photoresists. We have studied zirconium (Zr) and hafnium (Hf) based hybrid resists which have shown high sensitivity, they suffer though from scumming issues. On the other hand, our clusters based on zinc (Zn) which absorbs strongly in EUV seem to be free of scumming but still Zr and Hf outperform in terms of sensitivity. In an effort to understand better what controls sensitivity and scumming phenomena we have employed a combination of analytical techniques (Electrospray ionization mass spectrometry ESI-MS, X-ray photoelectron spectroscopy XPS, and Fouriertransform infrared spectroscopy FT-IR) to study the patterning mechanism in detail, in order to be able to optimize the development process and develop systems with optimal features.

The NanoCulture Plate (NCP) is a novel microstructural plate designed as a base for the three-dimensional culture of cells/tissues. This study examined whether or not the metabolic capability of human primary hepatocytes is well maintained during culture on NCPs. The hepatocytes formed aggregates after seeding and their ATP content was well maintained during culture for 21days. Expression of CYP1A2, 2B6, 2C9, 2C19, 2D6, 2E1 and 3A4 mRNAs was detected throughout the 21-day culture period. Addition of CYP substrate drugs (midazolam, diclofenac, lamotrigine and acetaminophen) resulted in the formation of multiple metabolites with a corresponding decrease in the amounts of the unchanged compounds. The inducers omeprazole, phenobarbital and rifampicin increased the levels of CYP1A2, 2B6 and 3A4 mRNAs by 110-fold, 12.5-fold and 5.4-fold, respectively, at day 2, compared with control human hepatocytes. CYP activities were also increased at 2days after inducer treatment (CYP1A2, 2.2-fold; CYP2B6, 20.6-fold; CYP3A4, 3.3-fold). The results indicate that the hepatocyte spheroids on NCP have detectable and inducible metabolic abilities during the 7-day culture period.

Ultrasound-guided cervical medial branch block (CMBB) is commonly performed to diagnose and treat head, neck, and shoulder pain. However, its use at the C7 level has been shown to be less accurate than at other levels, which may increase the chance of injury owing to the imprecision of needle site provided by the ultrasound guide. We report the first case of iatrogenic spinal cord injury from an ultrasound-guided C7 CMBB. The patient, upon receiving this procedure, had fainted shortly after experiencing an electrical sensation that ran from the neck to the toe. The patient complained of weakness and tingling sensation in the left upper extremity. Cervical magnetic resonance imaging revealed a hematoma in the cervical spinal cord, and an electrophysiological study, which was performed at 3 weeks after the incident, revealed an injury at the left C3-T2 anterior horn. After 2 months of rehabilitation, the patient showed moderate improvement in the strength of the left proximal upper extremity; however, there was no improvement in the strength of the left distal upper extremity. Therefore, we recommend caution when performing ultrasound-guided CMBB at the C7 level, as the guide particularly at this level is relatively inaccurate, posing a risk of spinal cord injury.