Resist one-component

The photoresist is sensitive to the incident radiation and it undergoes (photo) chemical transformations. Photoresists are complex formulations consisting of organic solvent, polymer, photoactive compound (PAC), base, and other chemicals that confer it desired properties. In one-component resists, the polymer is the photoactive compound, whereas in two- or multicomponent resists the photoactive compound undergoes photochemical transformation resulting in new species that interact with the radiation inert polymer, triggering transformations that alter the solubility in the exposed areas. 

In addition to the binary classification based on the imaging tone, resists can be divided on the basis of their design into 1) one-component and 2) multi-component systems (Fig. 4). One-component resists consist of pure radiation-sensitive polymers that must combine all the necessary attributes as mentioned above, and have long lost ground. The modern advanced lithography is ex-... 

It should be emphasized that one-component resists consisting of pure radiation-sensitive materials, which in modern times are comprised primarily of polymers that combine all of the necessary attributes of a resist, have now fallen out of favor. In contrast, modern advanced lithography relies almost exclusively on the multicomponent design concept in which resist functions are provided by separate components, comprising the resin/bmder on the one hand, and the photoactive compounds on the other. In these multicomponent systems, the resins/ binders are polymers and are typically inert to radiation, but can undergo radiation-induced reactions initiated by the photoactive components of the resists. ... 

In 1968 the Monsanto Company announced the availability of novel soluble low molecular weight polyphenylene resins. These may be used to impregnate asbestos or carbon fibre and then cross-linked to produce heat-resistant laminates. The basic patent (BP 1037111) indicates that these resins are prepared by heating aromatic sulphonyl halides (e.g. benzene-1,3-disulphonyl dichloride) with aromatic compounds having replaceable nuclear hydrogen (e.g. bisphenoxy-benzenes, sexiphenyl and diphenyl ether). Copper halides are effective catalysts. The molecular weight is limited initially by a deficiency in one component. This is added later with further catalyst to cure the polymer. 

The two-component waterborne urethanes are similar in nature to the one-component waterborne urethanes. In fact, many one-component PUD s may benefit from the addition of a crosslinker. The two-component urethanes may have higher levels of carboxylic acid salt stabilizer built into the backbone than is actually needed to stabilize the urethane in water. As a result, if these two-component urethane dispersions were to be used as one-component adhesives by themselves (without crosslinker), they would show very poor moisture resistance. When these two-component urethane dispersions are used in conjunction with the crosslinkers listed in Fig. 8, the crosslinkers will react with the carboxylic pendant groups built into the urethane, as previously shown in the one-component waterborne urethane section. This accomplishes two tasks at the same time (1) when the crosslinker reacts with the carboxylic acid salt, it eliminates much of the hydrophilicity associated with urethane dispersion, and (2) it crosslinks the dispersion, which imparts solvent and moisture resistance to the urethane adhesive (see phase V in Fig. 5). As a result of crosslinking, the physical properties may be modified. For example, the results may be an increase in tensile properties and a decrease in elongation. Depending upon the level of crosslinking, the dispersion may lose the ability to be repositionable. (Many of the one-component PUD s may... 

Resist materials can be classified as positive or negative on the basis of their radiation response as described in Section 3.1 and illustrated in Figure 1. Both resist types can be subdivided into two categories depending upon the basic nature of their design 1) one-component systems and 2) two-component systems (see Figure 2). One-component systems are polymers that combine radiochemical reactivity with etch resistance and film-forming characteristics. In two component systems, the resist is formulated from an... 

Poly(methyl methacrylate) (PMMA) is a classical one-component, positive resist system. PMMA is a single, homogeneous material that combines the properties of excellent film-forming characteristics, resistance to chemical etchants and intrinsic radiation sensitivity. 

COP, the familiar negative e-beam resist developed at Bell Laboratories, is an example of a one-component negative resist system. COP is a copolymer which has excellent film-forming characteristics, resistance to etchants, and intrinsic radiation sensitivity. 

Experimental determination of the quantum efficiency of photosensitive polymers of the sort that are used in one-component positive resist systems is a more complex experimental undertaking. Here the quantum efficiency is defined as the number of main chain scissions that occurs per photon absorbed. Guillet and coworkers at the University of Toronto have... 

The most common methods of growing crystals involve solidification from the melt (in the case of one-component systems) or crystallization from solution. Some of the methods for growing crystals from melt are described schematically in Fig. 3.6. In the Czochralski method, commonly known as the pulling technique, the material is melted by induction or resistance heating in a suitable nonreactive crucible. The melt temperature is adjusted to slightly above the melting point and a seed crystal is dipped into the melt. After thermal equilibration is attained, the seed is slowly lifted from the... 

Apart from multi-level layer resist systems, conventional positive-tone resists can be classified into two categories one-component and two-component systems. Classical examples of the former systems are polyfmethyl methacrylate), and poly (butene-1-sulfone) (2,3). Typical examples of the latter system are AZ-type photoresists, which are mixtures of cresol-formaldehyde-Novolak resins and a photoactive compound acting as a dissolution inhibitor... 

S buffer solution is any solution that resists large changes in pH. Buffer solutions work by containing two components. One component neutralizes any added base, and the other neutralizes any added acid. Effective buffer solutions can be prepared by mixing a weak acid with a salt of the weak acid. An example would be a mixture of acetic acid, C2H402, and sodium acetate, NaC2H402. This salt can be made by reacting acetic acid with sodium hydroxide. 

Finally, it must be pointed out that the adsorbent when it makes contact with a binary mixture, one component is selectively adsorbed by the solid adsorbent. In the flowing fluid, a trace of an adsorbable species is adsorbed from a relatively inert carrier. In addition, the heat effects can be ignored, as a result, isothermal conditions can be taken [9,103], The flow is fed at the top of the bed at a constant flow rate, and under conditions such that mass-transfer resistance is insignificant [2,103],... 

The catalyst does not make up part of the final epoxy network structure or have a significant effect on the final properties of the cured resin. Thus, the final cured properties of the epoxy system are primarily due to the nature of the epoxy resin alone. Homopolymerization normally provides better heat and environmental resistance than polyaddition reactions. However, it also provides a more rigidly cured system, so that toughening agents or flexibilizers must often be used. In adhesive systems, homopolymerization reactions are generally utilized for heat cured, one-component formulations. 

Dicyandiamide Latent cure Good elevated-temperature properties Good chemical resistance Good combination of tensile and peel strength Long elevated-temperature cure Insoluble in resin One-component adhesives Powder coatings Film and solid adhesives Laminates and other composites... 

Novel, toughened one-component epoxy structural adhesives based on epoxy-terminated polyurethane prepolymer incorporating an oxolidone structure were developed to provide improved toughness, fracture resistance and adhesive properties with good chemical and moisture resistance.21 The hybrid resin cures with a standard latent curing agent/accelerator. 

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