Non-chemically amplified resists for 193-nm immersion lithography: Influence of absorbance on performance

The feasibility of three polymer systems for use as non chemically amplified resists for 193 nm lithography are discussed. The three systems are polycarbonates, polyphthalaldehydes and polysulfones. In general it was found that increased absorbance resulted in higher sensitivity to 193 nm light. However, the exception to this was the polycarbonates, which were found to undergo crosslinking due to an alkene group present in the polymer backbone. Although polyphthalaldehydes were very sensitive, their absorbance values were too high to be useful in a commercial environment. Absorbing polysulfones were found to be sensitive to 193 nm light and initial patterning results have been presented

Non-CA resists for 193nm immersions lithography: Effects of chemical structure on sensitivity

Initial studies are presented on the use of polysulfones as non-chemically amplified resists (non-CARs) for 193 nm immersion lithography. Polynorbornene sulfone films on silicon wafers have been irradiated with 193 nm photons in the absence of a photo-acid generator. Chemical contrast curves and contrast curves were obtained via spectroscopic ellipsometry and grazing angle - attenuated total reflectance FTIR spectroscopy. Results were consistent with previously reported mechanisms for the degradation of aliphatic polysulfones with ionizing radiation. It was shown that E0 values could be reduced significantly by using a post exposure bake step, which propagated depolymerization of the polymer. Initial patterning results down to 50 nm half pitch were demonstrated with EUV photons

Sensitive polysulfone based chain scissioning resists for 193 nm lithography

Chain scissioning resists do not require addition of photoacid generators to function. Previously reported chain scissioning polysulfone resists were able to achieve enhanced sensitivity by incorporation of absorbing repeat units, but these groups also inhibited the depolymerization reaction, which could further enhance sensitivity. Here we report the development of sensitive polysulfone chain scissioning resists for 193 nm that are able to undergo depolymerization. The effect of depolymerization of LER is also discussed. These polymers underwent CD shrinkage upon overdose, which may be useful for double patterning processes

Polysulfone based Non-CA resists for 193nm immersion lithography: Effect of increasing polymer absorbance on sensitivity

The use of norbornene-based polysulfones as non-chemically amplified resists (non-CARs) for 193 nm immersion lithography was explored. Allylbenzene was incorporated into the polymer backbone to increase the absorbance of the polymers. The effect of polymer absorbance on sensitivity to 193 nm radiation was investigated. Polymer films on silicon wafers have been irradiated with 193 nm photons in the absence of a photo-acid generator. Chemical contrast curves (film thickness versus dose plots prior to solvent development) and contrast curves (film thickness versus dose plots after solvent development) were obtained by spectroscopic ellipsometry. The results show that E0 values could be reduced significantly by increasing the absorbance of the polymer

Global migration and factors influencing retention of Asian internationally educated nurses: a systematic review

Abstract Background Given nurses’ increasing international mobility, Asian internationally educated nurses (IENs) represent a critical human resource highly sought after within the global healthcare workforce. Developed countries have grown excessively reliant on them, leading to heightened competition among these countries. Hence, this review aims to uncover factors underlying the retention of Asian IENs in host countries to facilitate the development of more effective staff retention strategies. Methods A mixed-methods systematic review was conducted using the Joanna Briggs Institute methodology for mixed-method systematic review. A search was undertaken across the following electronic databases for studies published in English during 2013–2022: CINAHL, Embase, PubMed, Scopus, Web of Science and PsycINFO. Two of the researchers critically appraised included articles independently using the Joanna Briggs Critical Appraisal Tools and Mixed Methods Appraisal Tool (version 2018). A data-based convergent integrated approach was adopted for data synthesis. Results Of the 27 included articles (19 qualitative and eight quantitative), five each were conducted in Asia (Japan, Taiwan, Singapore and Malaysia), Australia and Europe (Italy, Norway and the United Kingdom); four each in the United States and the Middle East (Saudi Arabia and Kuwait); two in Canada; and one each in New Zealand and South Africa. Five themes emerged from the data synthesis: (1) desire for better career prospects, (2) occupational downward mobility, (3) inequality in career advancement, (4) acculturation and (5) support system. Conclusion This systematic review investigated the factors influencing AMN retention and identified several promising retention strategies: granting them permanent residency, ensuring transparency in credentialing assessment, providing equal opportunities for career advancement, instituting induction programmes for newly employed Asian IENs, enabling families to be with them and building workplace social support. Retention strategies that embrace the Asian IENs’ perspectives and experiences are envisioned to ensure a sustainable nursing workforce

Zyxin Is involved in fibroblast rigidity sensing and durotaxis

Focal adhesions (FAs) are specialized structures that enable cells to sense their extracellular matrix rigidity and transmit these signals to the interior of the cells, bringing about actin cytoskeleton reorganization, FA maturation, and cell migration. It is known that cells migrate towards regions of higher substrate rigidity, a phenomenon known as durotaxis. However, the underlying molecular mechanism of durotaxis and how different proteins in the FA are involved remain unclear. Zyxin is a component of the FA that has been implicated in connecting the actin cytoskeleton to the FA. We have found that knocking down zyxin impaired NIH3T3 fibroblast’s ability to sense and respond to changes in extracellular matrix in terms of their FA sizes, cell traction stress magnitudes and F-actin organization. Cell migration speed of zyxin knockdown fibroblasts was also independent of the underlying substrate rigidity, unlike wild type fibroblasts which migrated fastest at an intermediate substrate rigidity of 14 kPa. Wild type fibroblasts exhibited durotaxis by migrating toward regions of increasing substrate rigidity on polyacrylamide gels with substrate rigidity gradient, while zyxin knockdown fibroblasts did not exhibit durotaxis. Therefore, we propose zyxin as an essential protein that is required for rigidity sensing and durotaxis through modulating FA sizes, cell traction stress and F-actin organization