Polymer Bound Photobase Generators And Photoacid Generators For Pitch Division Lithography

The semiconductor industry is pursuing several process options that provide pathways to printing images smaller than the theoretical resolution limit of 193 nm projection scanners. These processes include double patterning, side wall deposition and pitch division. Pitch doubling lithography (PDL), the achievement of pitch division by addition of a photobase generator (PBG) to typical 193 nm resist formulations was recently presented. 1 Controlling the net acid concentration as a function of dose by incorporating both a photoacid generator (PAG) and a PBG in the resist formulation imparts a resist dissolution rate response modulation at twice the frequency of the aerial image. Simulation and patterning of 45 nm half pitch L/S patterns produced using a 90 nm half pitch mask were reported. 2 Pitch division was achieved, but the line edge roughness of the resulting images did not meet the current standard. To reduce line edge roughness, polymer bound PBGs and polymer bound PAGs were investigated in the PDL resist formulations. The synthesis, purification, analysis, and functional performance of various polymers containing PBG or PAG monomers are described herein. Both polymer bound PBG with monomeric PAG and polymer bound PAG with monomeric PBG showed a PDL response. The performance of the polymer bound formulations is compared to the same formulations with small molecule analogs of PAG and PBG.Chemical Engineerin

Photobase Generator Enabled Pitch Division: A Progress Report

Pitch division lithography (PDL) with a photobase generator (PBG) allows printing of grating images with twice the pitch of a mask. The proof-of-concept has been published in the previous paper[1, 2] and demonstrated by others[1]. Forty five nm half-pitch (HP) patterns were produced using a 90nm HP mask, but the image had line edge roughness (LER) that does not meet requirements. Efforts have been made to understand and improve the LER in this process. Challenges were summarized toward low LER and good performing pitch division. Simulations and analysis showed the necessity for an optical image that is uniform in the z direction in order for pitch division to be successful. Two-stage PBGs were designed for enhancement of resist chemical contrast. New pitch division resists with polymer-bound PAGs and PBGs, and various PBGs were tested. This paper focuses on analysis of the LER problems and efforts to improve patterning performance in pitch division lithography.Chemical Engineerin

Minutes 1876

https://place.asburyseminary.edu/freemethodistminutesyearbooks/1014/thumbnail.jp

Live imaging of wound inflammation in Drosophila embryos reveals key roles for small GTPases during in vivo cell migration

Aa robust inflammatory response to tissue damage and infection is conserved across almost all animal phyla. Neutrophils and macrophages, or their equivalents, are drawn to the wound site where they engulf cell and matrix debris and release signals that direct components of the repair process. This orchestrated cell migration is clinically important, and yet, to date, leukocyte chemotaxis has largely been studied in vitro. Here, we describe a genetically tractable in vivo wound model of inflammation in the Drosophila melanogaster embryo that is amenable to cinemicroscopy. For the first time, we are able to examine the roles of Rho-family small GTPases during inflammation in vivo and show that Rac-mediated lamellae are essential for hemocyte motility and Rho signaling is necessary for cells to retract from sites of matrix– and cell–cell contacts. Cdc42 is necessary for maintaining cellular polarity and yet, despite in vitro evidence, is dispensable for sensing and crawling toward wound cues

Antitumor activity from antigen-specific CD8 T cells generated in vivo from genetically engineered human hematopoietic stem cells

The goal of cancer immunotherapy is the generation of an effective, stable, and self-renewing antitumor T-cell population. One such approach involves the use of high-affinity cancer-specific T-cell receptors in gene-therapy protocols. Here, we present the generation of functional tumor-specific human T cells in vivo from genetically modified human hematopoietic stem cells (hHSC) using a human/mouse chimera model. Transduced hHSC expressing an HLA-A*0201–restricted melanoma-specific T-cell receptor were introduced into humanized mice, resulting in the generation of a sizeable melanoma-specific naïve CD8^+ T-cell population. Following tumor challenge, these transgenic CD8^+ T cells, in the absence of additional manipulation, limited and cleared human melanoma tumors in vivo. Furthermore, the genetically enhanced T cells underwent proper thymic selection, because we did not observe any responses against non–HLA-matched tumors, and no killing of any kind occurred in the absence of a human thymus. Finally, the transduced hHSC established long-term bone marrow engraftment. These studies present a potential therapeutic approach and an important tool to understand better and to optimize the human immune response to melanoma and, potentially, to other types of cancer

Bayesian inference reveals positive but subtle effects of experimental fishery closures on marine predator demographics

Global forage-fish landings are increasing, with potentially grave consequences for marine ecosystems. Predators of forage fish may be influenced by this harvest, but the nature of these effects is contentious. Experimental fishery manipulations offer the best solution to quantify population-level impacts, but are rare. We used Bayesian inference to examine changes in chick survival, body condition and population growth rate of endangered African penguins Spheniscus demersus in response to 8 years of alternating time-area closures around two pairs of colonies. Our results demonstrate that fishing closures improved chick survival and condition, after controlling for changing prey availability. However, this effect was inconsistent across sites and years, highlighting the difficultly of assessing management interventions in marine ecosystems. Nevertheless, modelled increases in population growth rates exceeded 1% at one colony; i.e. the threshold considered biologically meaningful by fisheries management in South Africa. Fishing closures evidently can improve the population trend of a forage-fish-dependent predator-we therefore recommend they continue in South Africa and support their application elsewhere. However, detecting demographic gains for mobile marine predators from small no-take zones requires experimental time frames and scales that will often exceed those desired by decision makers

The play is a prison : the discourse of Prison Shakespeare.

The relationship between Shakespeare and prison was brought into sharp focus during Shakespeare’s recent quad-centenary with a succession of works exploring Shakespeare’s value for the prison population. In this paper, we take this spike in activity as a point of departure for examining the discourse of Prison Shakespeare. This discourse, we argue, is underpinned by several intertwining and sometimes paradoxical accounts of social being: (i) psychoanalytic accounts; (ii) postmodern accounts; (iii) humanist accounts bound up with the idea of cultural unfolding; (iv) neoliberal accounts that champion heroic individualism. In our analysis, we respond to Pensalfini’s call for critical debate over the assumption that Shakespeare's plays have the power to both teach and liberate prisoners. We note how Prison Shakespeare is always in a struggle to escape the institutional power of both Shakespearean drama and the prison context itself, and the tendency of this work to provide a model of socialization into, rather than resistance against, what Bristol describes as the mode of subjectivity of the bourgeois political economy

Ornamental plants: annual reports and research summaries

The Ohio State University Extension Nursery, Landscape, and Turf Team (ENLTT) -- Extension Nursery, Landscape, and Turf Team (ENLTT) directory -- An evaluation of composts for landscape soil amendments / Mary Ann Rose and Hao Wang -- Aesthetic evaluation of crabapples at Secrest Arboretum in Wooster, Ohio: 1994-1995 / James A. Chatfield, Erik A. Draper, Kenneth C. Cochran, Peter W. Bristol and Charles E. Tubesing -- Evaluation of crabapples for apple scab at Secrest Arboretum in Wooster, Ohio: 1995 / Erik A. Draper, James A. Chatfield, Kenneth C. Cochran, Peter W. Bristol and Charles E. Tubesing -- Emergence, longevity, and aesthetic evaluations of flowers in ornamental crabapples at Secrest Arboretum in Wooster, Ohio: 1995 / Erik A. Draper, James A. Chatfield and Kenneth C. Cochran -- Environmental and cultural ornamental plant problems in Ohio: 1995 / Pamela J. Bennett and Jane A. Martin -- 1995 -A Challenging Year for Ohio golf courses / Joseph W. Rimelspach, John R. Street, Karl Danneberger, William E. Pound, Barbara Bloetscher -- Plant insect pest problems in Ohio: 1995 / Joseph F. Boggs, David J. Shetlar, Gary Yu Gao, Daniel Balser, Douglas C. Caldwell, Randall H. Zondag and James A. Chatfield -- Gypsy moth in Ohio: 1995 / Allan Baumgard, David F. James and Randall H. Zondag -- Landscape ornamental disease problems in Ohio: 1995 / James A. Chatfield, Nancy Taylor, Randall H. Zondag, Mary Ann Rose, Gary Yu Gao, Daniel R. Balser and David J. Shetlar -- The Response of native and naturalized trees to construction activity / T. Davis Sydnor, Joseph F. Boggs and Mary Ann Ros