Azide compounds, photosensitive

A photosensitive composition, consisting of an aromatic azide compound (4,4 -diazidodi-phenyl methane) and a resin matrix (poly (styrene-co-maleic acid half ester)), has been developed and evaluated as a negative deep UV resist for high resolution KrF excimer laser lithography. Solubility of this resist in aqueous alkaline developer decreases upon exposure to KrF excimer laser irradiation. The alkaline developer removes the unexposed areas of this resist. 

The photosensitive azide compound was 4,4 -diazidodiphenyl methane (m.p. 44.0 t). The poly(styrene-co-maleic acid half ester) was used as a resin matrix. 

Photosensitive systems composed of photoactive aromatic azide compounds and a variety of host polymers have been well known since the 1930s (la). Negative photoresists comprising an azide and a cyclized cw-l,4-polyiso-prene (structure 3.8) as a host polymer, such as Kodak s KTFR, have been... 

Cu(I) azides are photosensitive, and both the Cu(I) and azide groups appear to react independently. In addition, Cu" is oxidized when exposed to atmospheric oxygen. The normal Cu(I) azide, Cu(N3), is a white, crystalline solid. On account of its reactivity, however, it is usually obtained as a gray-green powder [175]. Exposure to light leads soon to a dark red product [1] while nitrogen is evolved [175]. The compound is insoluble in water and organic solvents. It is extremely sensitive to heat (temperature of explosion, 220°C [176], impact, and friction. 

These are lithographic plates and find application on offset presses. The photosensitive materials used include diazo monomers, diazo polymers, and diazo compounds, in conjunction with additive film formers such as epoxy resins, phenoKcs, poly(vinyl acetals), polyamides, azide compounds, unsaturated chalcone, cinnamate, stilbene, and vinyl polymers and dichromated colloids. Three kinds of metallic photolithographic plates are used. These are surface plates, deep-etch plates, and bimetahic or trimetallic plates. 

Of the following amine-reactive and photoreactive crosslinkers, the overwhelming majority use an aryl azide group as the photosensitive functional group. Only a few use alternative photoreactive chemistries, particularly perfluorinated aryl azide, benzophenone, or diazo compounds. For general background information on photoreactive crosslinkers, see Das and Fox (1979), Kiehm and Ji (1977), Vanin and Ji (1981), and Brunner (1993). 

Silver is a white, ductile metal occurring naturally in its pure form and in ores (USEPA 1980). Silver has the highest electrical and thermal conductivity of all metals. Some silver compounds are extremely photosensitive and are stable in air and water, except for tarnishing readily when exposed to sulfur compounds (Heyl et al. 1973). Metallic silver is insoluble in water, but many silver salts, such as silver nitrate, are soluble in water to more than 1220 g/L (Table 7.3). In natural environments, silver occurs primarily in the form of the sulfide or is intimately associated with other metal sulfides, especially fhose of lead, copper, iron, and gold, which are all essentially insoluble (USEPA 1980 USPHS 1990). Silver readily forms compounds with antimony, arsenic, selenium, and tellurium (Smith and Carson 1977). Silver has two stable isotopes ( ° Ag and ° Ag) and 20 radioisotopes none of the radioisotopes of silver occurs naturally, and the radioisotope with the longest physical half-life (253 days) is "° Ag. Several compounds of silver are potential explosion hazards silver oxalate decomposes explosively when heated silver acetylide (Ag2C2) is sensitive to detonation on contact and silver azide (AgN3) detonates spontaneously under certain conditions (Smith and Carson 1977). 

The bis(aryl)azide sensitizers must be soluble in the resin, thermally stable, and sensitive to the desired wavelength of light. A commonly used compound is 2,6-bis(4-azidobenzylidene)cyclohexanone, which absorbs at 360 nm (see structure). Conjugation extension and other structural changes can shift the absorption maximum to longer wavelengths and allow access to the other mercury lines at 405 and 436 nm. A number of bis(aryl)azides are efficient photosensitizers (21). Quantum yields, defined as the number... 

The explosive properties of a series of 5 amminecobalt(III) azides were examined in detail. Compounds were hexaamminecobalt triazide, pentaammineazidocobalt diazide, cis- and traw.v-tetraamminediazidocobalt azide, triamminecobalt triazide [1], A variety of hydrazine complexed azides and chloroazides of divalent metals have been prepared. Those of iron, manganese and copper could not be isolated cobalt, nickel, cadmium and zinc gave products stable at room temperature but more or less explosive on heating [2]. Some polyammine azido-metal nitrates of Cr, Ni and Cu were found to be explosively photosensitive. Replacement of ammonia by triethanolamine gave compounds smoothly photodecomposing [3]. 

Phenyl azide can yield benzotriazole on irradiation , but more generally products of self-insertion or of attack on the solvent are found to lead to azepines and related compounds " - . Photolysis of o-azidobiphenyls formed carbazoles by intramolecular cyclization similar to that found in thermolysis and an analogous intramolecular cyclization involving, e.g. a nitro group could occur (reaction 74) in direct photolysis but not apparently in photosensitized reactions when only azobiphenyl was formed in appreciable yield The... 

Aromatic azides are stable photosensitive compounds and some of them mixed in cycllzed rubber are practically used as photosensitive resines.(j ) Such photosensitive polymers as poly(vinyl p-azidobenzo-ate)(2 ) and poly(vlnyl p-azldoclnnamate)(3) are also Investigated. These photosensitive resines are known to be spectrally sensitized by triplet sensitlzers(l,2,3) But the energies E(Ti) of the lowest triplet states Ti of aromatic azides have not been known, because these compounds emit no phosphorescence( ) and the trials on the measurement of their Sq- Ti absorptions are failed(4,3) ... 

Several negative resists based on polymeric resin binders and azides as the photoactive compound have also been reported. These include resists based on poly(vinyl phenol) as the polymeric resin and various mono-azides as the photosensitive component such as 4-azidochalcone and its homologs (XIV, XV, XVI). ... 

A normal platinum azide is not known, but complex azides of both Pt(II) and Pt(IV) have been described. When investigating the latter, Curtius and Rissom [62] obtained red solutions of the potassium salt which exploded violently when heated, and a dark red residue, obtained upon concentration, exploded spontaneously with high brisance. The sensitivity disappears in combination with large organic cations or amine ligands, yielding compounds that decompose slowly when heated but are stable to impact. They are, however, photosensitive and will deteriorate within hours or days. 

Hg(N3)2 is somewhat photosensitive and turns yellow in bright daylight, owing to the appearance of colloidal mercury. It also decomposes thermally [2], with gas evolution starting at 212°C, followed by discoloration at 220°C and explosion at 300°C. The compound is slightly soluble in cold water (0.257 g in 100 g solution at 20°C) [223] in hot water it dissolves more readily, without noticeable hydrolysis. It also dissolves in ethanolamine, apparently without chemical reaction [227], and in hydrofluoric acid, as a cation complex. Upon evaporation of the acid, the azide appears unchanged [196]. 

Lead azide is a white, crystalline solid which is sparingly soluble in water [276] its solubility may be enhanced by complexation [157,276]. Hydrolysis at room temperature is negligible [197]. The compound is somewhat photosensitive and, unless handled under yellow light, appears buff or gray [175,176]. It is highly sensitive to impact, heat shock, and friction and explodes with high brisance [197]. Thermal decomposition leads to explosion above 345 C [2,176]. 

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