Deep UV image processing for 0.35 micron lithography in production JESSI subprogramme equipment and materials technology

For deep UV image processing in lithography for chip production a stable resist process was developed based on the SUCCESS resist concept of the joint European project 'JESSI E 162'. Starting from poly(p-hydroxystyrene) the formulation of delay-stable positive photoresists with good resolution capabilities and dry-etch resistance was obtained by applying additives against T-topping and by adjusting the protective group chemistry for linewidth stability. The major achievements are: linewidth stability for #>=# 0.35 #mu#m lines during delay times up to 120 min between exposure and post-exposure bake, 0.24 #mu#m lines stable for 30 min, linearity down to 0.35 #mu#m, resolution of 0.22 #mu#m with phase-shift mask, dry etch resistance better than conventional novolac resists. Chemically amplified resists have been modelled using the effective acid concept. (WEN)Available from TIB Hannover: F96B272+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman

Entwicklung neuer photoleitender Polymersysteme

In order to obtain fast organic photoconductors with a charge carrier mobility >10"-"4 cm"2/Vxs and with improved processing behaviour, liquid crystalline systems were prepared and characterized. Besides some calamitic liquid crystals with smectic and nematic mesophases, mainly discotic columnar mesophases with efficient charge transport along the one-dimensional ordered columns were synthezised and subsequently studied in time-of-flight, transient absorption, quantum yield and steady-state photoconductivity experiments. For the studied systems structure-property relationships could be established between structure, order, mobility, doping with electron acceptors, photoconductivity and mechanic properties. It is demonstrated that doped electron-rich hexaalkyloxytriphenylenes act as excellent hole conductors with a charge carrier mobility up to 10"-"3 cm"2/Vxs in the liquid crystal phase. (WEN)SIGLEAvailable from TIB Hannover: F95B1202+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Forschung und Technologie (BMFT), Bonn (Germany)DEGerman

Modeling the proton sponge hypothesis: Examining proton sponge effectiveness for enhancing intracellular gene delivery through multiscale modeling

Dendrimers have been proposed as therapeutic gene delivery platforms. Their superior transfection efficiency is attributed to their ability to buffer the acidification of the endosome and attach to the nucleic acids. For effective transfection, the strategy is to synthesize novel dendrimers that optimize both of these traits, but the prediction of the buffering behavior in the endosome remains elusive. It is suggested that buffering dendrimers induce an osmotic pressure sufficient to rupture the endosome and release nucleic acids, which forms to sequestrate most internalized exogenous materials. Presented here are the results of a computational study modeling osmotically driven endosome burst or the \u27proton sponge effect.\u27 The approach builds on previous cellular simulation efforts by linking the previous model with a sponge protonation model, then observing the impact on endosomal swelling and acidification. Calibrated and validated using reported experimental data, the simulations offer insights into defining the properties of suitable dendrimers for enhancing gene delivery as a function of polymer structure. © 2012 Taylor & Francis