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Thermal decomposition of bis(trialkylphosphine)-3,3,4,4-tetramethylplatinacyclopentanes in hydrocarbon solvents yields two major products: 2,2,3,3-tetramethylbutane and 1-methyl-l-tert-butylcyclopropane. The former appears to be generated by heterogeneous process(es) catalyzed by platinum(0) (colloidal and/or solid) formed during the decomposition; the latter is the product of a homogeneous reaction sequence. The existence of competing heterogeneous and homogeneous reaction pathways complicates the study of this thermal decomposition. The addition of mercury(O) to the system selectively suppresses the heterogeneous reaction by poisoning the bulk platinum (0). This technique has been tested in one well-defined model system-the homogeneous hydrogenation of dirieopentylbis(triethylphosphine)platinum(II) to dihydridobis(triethylphosphine)platinum(lI) and neopentane in the presence of the heterogeneous platinum(0)-catalyzed hydrogenation of 1-methylcyclopentene to methylcyclopentane-and found to eliminate the heterogeneous reaction while leaving the homogeneous one essentially unaffected. Application of this technique to the thermal decomposition of 3,3,4,4-tetramethylplatinacyclopentane simplifies the reaction by eliminating 2,2,3,3-tetramethylbutane as a product. Similarly, addition of mercury(O) to solutions containing H2 and (l,5-cyclooctadiene)dimethylplatinum(II) in cyclohexane suppresses the autocatalytic, heterogeneous platinum-catalyzed conversion of the organoplatinum compound to (inter alia) cyclooctane, methane, and platinum(O). In other reactions examined-especially the high-temperature thermal decompositions of (l,5-cyclooctadiene)dineopentylplatinum(II) and of cts-bis(cyclopentyldimethylphosphine)dimethylplatinum(II) in hydrocarbon solvents-mercury poisoning does not successfully separate homogeneous and heterogeneous reactions. In the latter instance, an additional complicating processapparent reaction of mercury(O) with the organoplatinum compound-introduces reaction paths which seem to generate methyl radicals. The paper includes a simple preparation of l,4-dihalo-2,2,3,3-tetramethylbutane and illustrates the use of this material as a reagent for the preparation of 3,3,4,4-tetramethylmetallacyclopentanes via the corresponding di-Grignard reagents.

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Secondary electrons play critical roles in several imaging technologies, including extreme ultraviolet (EUV) lithography. At longer wavelengths of light (e.g. 193 and 248 nm), the photons are directly involved in the photochemistry occurring during photolysis. EUV light (13.5 nm, 92 eV), however, first creates a photoelectron, and this electron, or its subsequent daughter electrons create most of the chemical changes that occur during exposure. Despite the importance of these electrons, the details surrounding the chemical events leading to acid production remain poorly understood. Previously reported experimental results using high PAG-loaded resists have demonstrated that up to five or six photoacids can be generated per incident photon. Until recently, only electron recombination events were thought to play a role in acid generation, requiring that at least as many secondary electrons are produced to yield a given number of acid molecules. However, the initial results we have obtained using a Monte Carlo-based modeling program, LESiS, demonstrate that only two to three secondary electrons are made per absorbed EUV photon. A more comprehensive understanding of EUVinduced acid generation is therefore needed for the development of higher performance resists.

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The 2007 International Technology Roadmap for Semiconductors (ITRS) 1 specifies Extreme Ultraviolet (EUV) lithography as one leading technology option for the 32nm half-pitch node, and significant world wide effort is being focused towards this goal. Readiness of EUV photoresists is one of the risk areas. In 2007, the ITRS modified performance targets for high-volume manufacturing EUV resists to better reflect fundamental resist materials challenges. For 32nm half-pitch patterning at EUV, a photospeed range from 5-30 mJ/cm 2 and low-frequency linewidth roughness target of 1.7nm (3σ) have been specified. Towards this goal, the joint INVENT activity (AMD, CNSE, IBM, Micron, and Qimonda) at Albany evaluated a broad range of EUV photoresists using the EUV MET at Lawrence Berkeley National Laboratories (LBNL), and the EUV interferometer at the Paul Scherrer Institut (PSI), Switzerland. Program goals targeted resist performance for 32nm and 22nm groundrule development activities, and included interim relaxation of ITRS resist performance targets. This presentation will give an updated review of the results. Progress is evident in all areas of EUV resist patterning, particularly contact/via and ultrathin resist film performance. We also describe a simplified figure-of-merit approach useful for more quantitative assessment of the strengths and weaknesses of current materials.

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One unique aspect of 193i lithography is the use of water situated between the final lens element and the resist. The resist stack (with or without topcoat) on the wafer is dynamically exposed through this water with the step-and-scan process. The photoacid generator (PAG), quencher, and other small molecular components of the resist may leach into this water. These leached components contaminate the water and may degrade resist performance. This contaminated water can additionally contaminate the lens and wafer stage of the scanner. To master these leaching problems, we must understand the dynamics of resist leaching, transportation of leached contaminates in the immersion water, and the impact of these contaminants on the lens during exposure.Additionally, water can penetrate the topcoat and diffuse into the resist film. This penetration and diffusion of water can cause the topcoat or the resist to swell, which will affect their lithographic performance. This chapter specifically addresses the following issues: (1) leaching test methods, (2) leaching dynamics, (3) leaching with 193-nm exposure, (4) pre-rinse to partially remove leached contaminants, (5) lens contamination caused by resist leaching, and (6) water uptake in resist film.