Resist sensitivity enhancement

As expected, the incorporation of pendant unsaturation in the resists greatly enhances sensitivity as demonstrated by a comparison of the contrast curves for poly(N-aiiyl maleimide-VBC) and the structurally similar poiy(N-ethyl maleimide-VBC) (Figure 4). Both polymers have similar molecular weights and nearly identical mass absorption coefficients but the allyl-containing copolymer is 5X faster. 

MLR systems offer many advantages in optical, e-beam, x-ray, and ion-beam lithography. An advantage common to all imaging methods is in enhancement of resist sensitivity. As the resolution and the aspect ratio requirements are separated in an MLR system, faster resists that are usable only for low aspect ratio images can now be candidates for the top layer. Other advantages of MLR systems differ from one imaging method to the other. They will be discussed separately. 

Sidhu, A. B., Valderramos, S. G., and Fidock, D. A. (2005). PfMDRl mutations contribute to quinine resistance and enhance mefloquine and artemisinin sensitivity in Plasmodium... 

The resist sensitivity is a very important parameter to be considered as it is directly related to wafer throughput and therefore device manufacturing cost. Thus, sensitivity enhancement was a primary research activity in the field of microlithography in the 1970s and early 1980s. However, the enhancement of sensitivity achieved at that time was too incremental and marginal. Quantum yields, expressed as the number of molecules transformed per photon absorbed, characterize the efficiency of photochemical events. Typical diazonaphthoquinone has a quantum yield of 0.2-0.3, which means that three to five photons are needed to convert a single molecule of the photoactive compound. An in-... 

OTFT response repeatability and enhancement, achieved with the gate bias, are apparent advantages over traditional chemiresistor sensors, whose response is a single parameter without any possibility to be modified. A resistor is a two-terminal device giving a resistive response, which is completely determined by the bnlk properties of the material used. It is of particular interest to investigate whether, besides a response enhancement, OTFTs are able to deliver a sensitivity enhancement no clear evidence of this phenomenon has been given and it is not yet well nnderstood which parameters control this important analytical property in OTFT sensors. 

Raw Materials. PVC is inherently a hard and brittle material and very sensitive to heat it thus must be modified with a variety of plasticizers, stabilizers, and other processing aids to form heat-stable flexible or semiflexible products or with lesser amounts of these processing aids for the manufacture of rigid products (see Vinyl polymers, vinyl chloride polymers). Plasticizer levels used to produce the desired softness and flexibihty in a finished product vary between 25 parts per hundred (pph) parts of PVC for flooring products to about 80—100 pph for apparel products (245). Numerous plasticizers (qv) are commercially available for PVC, although dioctyl phthalate (DOP) is by far the most widely used in industrial appHcations due to its excellent properties and low cost. For example, phosphates provide improved flame resistance, adipate esters enhance low temperature flexibihty, polymeric plasticizers such as glycol adipates and azelates improve the migration resistance, and phthalate esters provide compatibiUty and flexibihty (245). 

Bacteria produce chromosomady and R-plasmid (resistance factor) mediated P-lactamases. The plasmid-mediated enzymes can cross interspecific and intergeneric boundaries. This transfer of resistance via plasmid transfer between strains and even species has enhanced the problems of P-lactam antibiotic resistance. Many species previously controded by P-lactam antibiotics are now resistant. The chromosomal P-lactamases are species specific, but can be broadly classified by substrate profile, sensitivity to inhibitors, analytical isoelectric focusing, immunological studies, and molecular weight deterrnination. Individual enzymes may inactivate primarily penicillins, cephalosporins, or both, and the substrate specificity predeterrnines the antibiotic resistance of the producing strain. Some P-lactamases are produced only in the presence of the P-lactam antibiotic (inducible) and others are produced continuously (constitutive). 

Likewise, dead sharp corners or notches subjected to tensile loads during impact may decrease the impact resistance of a product by acting as stress concentrators, whereas generous radii in these areas may distribute the tensile load and enhance the impact resistance. This point is particularly important for products comprised of materials whose intrinsic impact resistance is a strong function of a notch radius. Such notch sensitive materials are characterized by an impact resistance that decreases drastically with notch... 

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