Generators, photoacid

Fig. 21. Representative nonionic photoacid generators. A variety of photochemical mechanisms for acid production ate represented. In each case a sulfonic acid derivative is produced (25,56,58—60). (a) PAG that generates acid via 0-nitrobenzyl rearrangement (b) PAG that generates acid via electron transfer with phenohc matrix (c) PAG that is active at long wavelengths via electron-transfer sensitization (d) PAG that generates both carboxylic acid and...

To achieve the best overall resist performance, the optimum PAG for a given resist system, whether ionic or nonionic, must balance the functional properties Hsted eadier in this section. The development of new photoacid generators, and the characterization of their functional properties, ate considered key to the design of resists with increased levels of performance. 

Photoresist appHcations in the microelectronics industry have also been disclosed (340). Thermally stable ben2yl sulfonate esters based on 2-methyl-3-nitroben2otrifluoride [6656-49-1] can serve as nonionic photoacid generators to promote a cascade of reactions during irradiation of the resist. 

Phosphoms pentoxide-methanesulfonic acid (PPMA), 315 Phosphorylation, 187 Photoacid generator (PAG), 317 Photoluminescence, 490 Photosensitive polyimides, 270-271, 292 PHRRs. See Peak heat release rates (PHRRs)... 

Nonionic latexes (latices), 19 855 Nonionic photoacid generators, 15 167-168 Nonionic polymers... 

PhoStrip process, as advanced wastewater treatment, 25 907 Photoablation, 20 278 Photoacid generators (PAGs), 10 521 ... 

This basic approach to chemical amplification was subsequently extended by Ito et al. [3] through resist formulations incorporating appropriately chosen triaryl sulfonium or diaryliodonium salt. For example, end-capped poly(phthalaldehyde) used in combination with an onium salt photoacid generator is an excellent self-... 

The imaging process involving polymers or 1 used in combination with a photoacid generating compound is outlined in Figure 6. Spin-coated films of polymer ... 

In this paper we report on the use of trifluoro-methanesulfonates (Table 1) of 4-N, N-dimethylamino-benzenediazonium (Dl) and 4-methoxybenzene-diazonium (D2) as CEL dyes, negative working sensitizers, and photoacid generators for chemical amplification resist systems(11). 

Photoacid generator. D1 (4 wt%) was mixed with poly(glycidyl methacrylate) (PGMA) (20 wt%) in ethyl cellosolve acetate. The mixture was spin-coated on a silicon wafer and baked at 80V for 1 minute. Exposure was performed with a 600-W Xe-Hg lamp in conjunction with a UVD2 filter. The resist was developed in a mixture of methyl ethyl ketone to ethanol (7/1 w/w). 

Fig. 7 Novel patternable block copolymers to achieve spatially controlled nanostructures, a An asymmetric PaMS-fc-PHS copolymer/photoacid generator/crosslinker solution was spin-coated on a silicon substrate and formed vertical PaMS cylinders due to rapid solvent evaporation, b 248 nm stepper exposure and subsequent development to form micropatterns with features as small as 400 nm. c Strong UV irradiation under high vacuum to remove PaMS, thus generating patterned nanochannels...

Scheme 49) [148], Recently, it has been demonstrated that phenolic sulfonate esters used as photoacid generators cleave into radical fragments the resulting phenoxyl radical has been detected by transient optical absorption [149], Similar photochemical rearrangements have been reported in pyrymidinic systems [150], An example is shown in Scheme 50 [151]. 

As with radical polymerization, some studies have used well-established IP-initiators under 2P excitation conditions. For example, the commercially available photoacid generator p.l (Fig. 18), which has a peak cross section of only 16 GM at a photon wavelength of 5 3 0 nm [ 169 ], has b een used to fabricate... 

Both writing and recording were accomplished by two-photon excitation of a spin-coated film containing fluorene 3, the photoacid generator, and polystyrene or, alternatively, in which writing was accomphshed by xy scans... 

Fig. 31 Time-dependent UV-visible absorption spectra of the photolysis of 3 and photoacid generator at photolysis times from f = 0 to 120 s...

Resist compositions were prepared consisting of the step 2 product (80 g), the photoacid generator, triphenylsulfonium nonafluorobutanesulfonate, (4.4 g), the base, tri-(2-methoxymethoxyethyl)amine (0.94 g), and solvents 1-methoxyisopropyl acetate 560 g) and cyclohexanone (240). Compositions were filtered through a Teflon filter with a pore diameter of 0.2 pm and then heated to 50°C for 20 hours and cooled. A polymer having an Mn of 7200 Da was then isolated. 

Kobayashi et al. (3) developed unique sulfate salts and derivatives as photoacid generators, (VI), for use in resist compositions and patterning processes. 

TABLE 1. Effectiveness of Experimental Photoacid Generators as Latent Adds"... 

Polymers based on COCs that have been described for photoresists are schematically shown in Figure 2.3. In addition, to the formulation a photoacid generator, di-(4-fcrf-butylphenyl)iodonium-10-camphor sulfonate is added. Other optional additives include anti-striation agents, plasticizers, speed enhancers, etc. Ethyl lactate acts as a solvent (61). Several other types of photoacid generators have been described (62). 

GALLIUM AND GALLIUM COMPOUNDS] (Vol 12) PAGs. See Photoacid generators. 

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