High‐Modulus Spin‐On Organosilicate Glasses for Nanoporous Applications

Abstract

Nanoporous glasses, that is, structural glasses with large quantities of nanoscale porosity, are the cornerstone of several emerging technologies. The most prominent example is the semiconductor industry where interlayer dielectric (ILD) insulator films are critically needed to both reduce the resistance-capacitance time delay of the interconnect circuitry and reduce the cross-talk between adjacent conduction lines. For next-generation semiconductors these materials need an ultralow dielectric constant (k < 2.2) while being compatible with patterning processes where the minimum features are smaller than 40 nm. [1][2][3][4][5][6] These structures, owing to their size and dielectric requirements, can only be realized by introducing large quantities of nanoscale porosity. Other technologies where nanoporous glasses are of significant interest include catalyst supports, [7] separations and membranes, [8] laser materials, [9] optical waveguides, [10] sensors, [11] and applications in biotechnology. [12,13]

Low‐kMaterials: Recent Advances

“…Nevertheless, it was observed that at a dielectric constant of ∼2.3, the Young's modulus doubles when the MTMS/BTASE ratio is increased from 100:10 to 100:90 [169]. This result is in good agreement with a study on neat films showing the significant impact on the Young's modulus of adding 10 to 100 mol % of BTASE to MTMS [172]. Still, the addition of porosity to MTMS/BTASE copolymers leads to an important decrease of the mechanical properties, even at low porogen loadings.…”

Structural Evolution of Silica Gel and Silsesquioxane Using Thermal Curing

“…12 Existence of this peak indicates the presence of a highly symmetrical molecular structure such as closed cage. The peak at around 1050 cm À1 is attributed to the (Si-O) 4 ring symmetric stretch vibration mainly from asymmetric random network structures such as open cage and short ladder. 12 Indeed, the IR spectrum of a commercial octamethyl POSS, which is a well-defined and highly symmetric T8 cage, has one strong, narrow Si-O stretching band at 1107 cm À1 instead of two broader Si-O stretching bands.…”

“…Based on quantum calculation, there should be a broad distribution in the number of Si-O tetrahedron per ring. 11 Relatively, the (Si-O) 4 and (Si-O) 6 rings are more predominating and thus have been better studied among all the Si-O rings. The (Si-O) 4 ring forms several structures such as open cage, closed cage, and ladder.…”

“…11 Relatively, the (Si-O) 4 and (Si-O) 6 rings are more predominating and thus have been better studied among all the Si-O rings. The (Si-O) 4 ring forms several structures such as open cage, closed cage, and ladder. The IR absorption peak at around 1150 cm À1 arises from (Si-O) 4 ring asymmetric stretch vibration.…”

“…The (Si-O) 4 ring forms several structures such as open cage, closed cage, and ladder. The IR absorption peak at around 1150 cm À1 arises from (Si-O) 4 ring asymmetric stretch vibration. 12 Existence of this peak indicates the presence of a highly symmetrical molecular structure such as closed cage.…”