Solubility resistance issues

It should be pointed out that the solubility change in all chemically amplified resists (CARs) occurs only in the dark reaction during the PEB. Some of the CARs such as acetal and ketal systems have low activation energy, so deprotection can occur with low-temperature PEBs or even at room temperature. In the absence of thermally driven diffusion such as in acetal and ketal resist systems, BARCs must be used for resists with such low PEB temperatures, which are significantly lower than the soft bake temperature, in order to control reflectivity issues associated with standing waves. 

There is, however, a penalty. Precisely because it is so compact and water resistant, fat is harder to mobihse and transport than freely water-soluble sugars. The body, therefore, has to resort to elaborate mechanisms to move fat round the body, and as we shall see these are crucially related to health issues, especially heart disease. 

Solubility behaviour in solvents is far less an issue in latex technology than in solvent-borne polymer products. In the latter, choice of solvent or solvoit blends for polymeri2ation and application, e.g. spraying and diying characiois-tics, is paramount and a large element of the technology. >Mth latex systems, the principal issue is usually resistance of the final product to attack by solvents. 

Silicone resins, particularly siloxysilicates, are utilized in conditioning formulations for several purposes. These materials have been reported to increase the deposition and substantivity of dimethicone or dimethiconol fluids. Substantivity increases markedly as the proportion of resinous silicone to dimethylsiloxane increases, the improvement being directly related to the decreased solubility of the resin. Multilayer deposition is reported to be limited thus buildup is not considered to be an issue (92,100,174). Siloxysilicate resins have also been utilized in conditioning formulations to impart mild set retention properties to the hair. In addition to daily use conditioning products, the silicone resins may be incorporated into hairsprays, mousses, gels, and so forth, to provide humidity resistance as well as improved set retention properties, without detracting from dry hair aesthetics. The silicone resins are frequently formulated into these products in conjunction... 

The solubility of the PAG in the solid polymeric matrix can influence CA resist performance (63). This is a particular issue for the ionic oniiun salts if the polarities of polymer and PAG are sufficiently different, phase segregation will occur, and the poor mixing of photoacid and polymer effectively reduces the efficiency of catalyzed deprotection. Additionally, resist contrast can be affected when the solubility of the photoproducts differs from that of the original onium salt. In fact onium salts can serve as dissolution inhibitors in novolac polymers, analogous to diazonaphthoquinones, even in the absence of any acid-sensitive chemical function on the poljuner (27). 

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