Bridged Bisimide Polysilsesquioxane Xerogels:  New Hybrid Organic−Inorganic Materials

Hobson, Stephen; Shea, Kenneth J.

doi:10.1021/cm960440i

Cited by 73 publications

(53 citation statements)

References 44 publications

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“…[34] Finally, Shea et al have demonstrated that the hardnesses measured for bridged bisimide polysilsesquioxane xerogels were intermediate between nylon-6 and SiO 2 . [35] While these studies empirically confirm that incorporation of organic moieties into sol-gel glasses can reduce their brittleness, no models were presented to rationalize the contribution of the organic substructure to the mechanical properties. In this study, the contribution of the organic bridge to the oxycarbosilanes fracture resistance is estimated and the results are reported in table 1.…”

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confidence: 98%

Molecular Network Reinforcement of Sol–Gel Glasses

et al. 2007

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Nanoporous materials are often accessed by a supramolecular approach using soft matter templates. Porous silicates and organosilicates synthesized by wet chemistry processes have been intensively studied for the last 20 years. Due to the versatility of the sol-gel chemistry, thermally sensitive bonds, organic molecules [1] and polymers [2] can be introduced either at the pore surfaces or in the network, and pore size, distribution and organization can be controlled as well.[3] The combination of the most important properties of the inorganic and organic components, coupled with the control of the "empty space" has suggested many potential applications for these materials.[4] For example, several thin-film applications in emerging optical, electronic, biological and filtration technologies have been envisioned. [5,6] Until now, a major roadblock in the realization of technological applications for these materials seems to be their poor mechanical properties. Indeed, the incorporation of pores into brittle glasses often has a catastrophic effect on their mechanical and fracture properties. This behavior is even more pronounced when moving from silicate to organosilicate materials (ORMOSILS) due to a decrease in network atom connectivity, impacting potential applications for these materials. A case in point is the observation that the fracture energy value, G c , for dense methylsilsesquioxane (MSSQ) glass is typically less than 5 J.m -2 , as compared to 10 J.m -2 for SiO 2 . [7] The presence of methyl substituents, while useful to lower the dielectric constant, generate free volume and impart hydrophobicity, simultaneously reduces the density, modulus, hardness and fracture energy. [7][8][9][10] We have recently demonstrated that these organosilicates show a strong power relationship dependence between film density and mechanical properties (e.g. modulus and fracture resistance), resulting in a rapid decay of the latter with increase in porosity. [7] For MSSQ materials, unfortunate consequences of this are: a) at low level of porosity the modulus decreases extremely rapidly (e.g. 50 % reduction at 15 vol.% porosity), b) at higher porosities (> 30 %), the modulus vs density curves tend to converge, abrogating any anticipated benefits by starting from dense materials with higher modulii.[11] Without acceptable fracture resistance, porous organosilicate glasses would be of little utility in any of the applications cited above. This statement is especially applicable to microelectronics, where dense organosilicate materials containing varying amount of Si-Me substitutents (k = 2.7-3.0) are currently used as the insulating layers in 90 nm interconnect technology, [12,13] and porous analogs will be implemented in future electronic devices. [14,15] Escalating integration issues are anticipated for materials with increased porosity since many of the integration processes require good mechanical properties (e.g. chemical mechanical polishing, chip dicing, wire bonding, etc). [16,17] Mechanical instability and the associated...

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confidence: 98%

Molecular Network Reinforcement of Sol–Gel Glasses

et al. 2007

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“…The observation that incorporation of organic moieties into sol-gel glasses can reduce their brittleness [156][157][158][159][160] has drawn the attention of the semiconductor industry. However, in order to be viable candidates for application in the BEOL, the silicon precursors to these hybrid materials should be low cost, commercially available or readily prepared on a large scale.…”

Section: Hybrid Organic-inorganic: Oxycarbosilanesmentioning

confidence: 99%

Low‐kMaterials: Recent Advances

Dubois¹,

Volksen²

2012

Advanced Interconnects for ULSI Technology

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“…Furthermore, inhomogeneous dispersion of two phases and leaching of the photoactive molecules frequently occur in this sort of hybrid materials for which the concentration of luminescent centers is also largely decreased. In this way, a few novel studies in terms of the covalently bonded hybrids have appeared and the as-derived molecular-based materials exhibit monophasic appearance even at a high concentration of metal complexes [12][13][14][15][16][17][18][19][20][21][22][23][24] co-workers have been concentrated on complexes of rare earth-pyridine-dicarboxylic acid or their derivatives and the molecular-based dicarboxylic acid derivative materials have exhibited strong emissions. Zhang et al started to modify 1,10-phenanthroline and di-pyridine in order to prepare the determined molecular-level hybrid materials [12,13].…”

Section: Introductionmentioning

confidence: 99%