Design photoacid generator

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. 

The performance of the resist is controlled through the chemistries associated with each component. Using one 193-nanometer resist concept as an example, each component—the matrix resin, the dissolution inhibitor, and the photoacid generator—must be designed to be compatible with each other, but equally importantly, they must be compatible with the overall device fabrication process. Table 3.1 lists a number of materials requirements and the associated desired molecular characteristics. 

The photoacid generators used are mostly organic-based onium salts, designed to be soluble in both the casting and the developing solvent. Remarkably, some of... 

Figure 1 outlines the three resist approaches that we have examined employing resins based upon alternating copolymers of maleic anhydride and cycloolefins. Two of these, the three component and hybrid approaches depend upon the use of a DI to improve resolution and further enhance plasma etching resistance. In this pq)er we will detail our work on the design, synthesis and use of cycloolefin-maleic anhydride based resins, photoacid generators and novel multifunctional DIs for 193 nm lithography. 

A number of companies sell resists specifically engineered and optimized to work with particular NIL equipment. These resists were designed to have enhanced etch resistance and mold-release capabilities. Micro Resist Technology GmbH supplies an epoxy-based prepolymer that has photoacid generator (PAG) molecules incorporated and is sold under the trade name of mr-L 6000. ... 

A novel intra-ion-pair electron(i) transfer cleavage of the —C-B— bond is reported by Chatterjee et al. [98] from the photoreaction of triphenyl alkyl borate salts of cyanine dye (110) to generate a carbon-centered radical (113) whose utility for initiating a free radical polymerization reaction has been demonstrated (Scheme 26). An intramolecular concerted bond cleavage/coupling process is described [99] from phenyl anthracene sulphoniiun salt derivatives as a part of designing a novel Photoacid system. 

The design concept of chemical amplification is based on generation of a chemically stable catalytic species (commonly referred to as a photoacid and designated as a proton H, as illustrated in Fig. 17.22 for a resist system comprising a copolymer—poly(4-hydroxystyrene-co-4-t-butyloxycarbonyloxystrene)—in... 

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