Directed lithographic application

Typical lithographic applications of dye-sensitized photopolymerization today include direct laser imaging of printed wiring boards, based on a visible laser-sensitive resist (Riston LV ) developed by Dupont. ... 

Precursor polymers may be applicable in direct writing applications (5). That is, they will be convertable, either by UV, X-ray or electron beam radiation from an insulating phase to a conducting phase in one step. Reduction in processing steps is of interest in any lithographic process. 

The use of reverse ATRP enlarges the scope of substrate polymers for controlled polymerizations even further because the required radical initiators can in many cases be provided more easily than ATRP initiators on surfaces of inert polymers. For example, poly(vinylidene fluoride) microfiltration membranes were irradiated with UV light and then exposed to air to create hydro(peroxide) species [11]. These were then used to initiate the reverse ATRP of methyl methacrylate in the presence of copper(I) chloride, 2,2 -bipyridine, and benzoylperoxide (Figure 3.5). Similar reaction schemes are applicable to (hydro)perox-ide patterns created directly on polymer surfaces using the lithographic methods discussed in Chapter 2. 

Porous III-V semiconductors are of great interest because of possible applications in optoelectronics and photonics. Study of the luminescence from porous direct band gap semiconductors such as GaAs and InP presents an additional interest because quantum confinement effects are well established in two-, one-, and zero dimensional electron systems prepared on crystalline III-V materials. Thus it would be possible to compare the light-emission properties between structures obtained by porous-etching and those produced in well-characterized lithographically defined structures directly. GaP was studied for comparison because it is an indirect band gap. 

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