Evans Austin M, Giri Ashutosh, Sangwan Vinod K, Xun Sangni, Bartnof Matthew, Torres-Castanedo Carlos G, Balch Halleh B, Rahn Matthew S, Bradshaw Nathan P, Vitaku Edon, Burke David W, Li Hong, Bedzyk Michael J, Wang Feng, Brédas Jean-Luc, Malen Jonathan A, McGaughey Alan J H, Hersam Mark C, Dichtel William R, Hopkins Patrick E
Department of Chemistry, Northwestern University, Evanston, IL, USA.
Department of Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, VA, USA.
Nat Mater. 2021 Aug;20(8):1142-1148. doi: 10.1038/s41563-021-00934-3. Epub 2021 Mar 18.
As the features of microprocessors are miniaturized, low-dielectric-constant (low-k) materials are necessary to limit electronic crosstalk, charge build-up, and signal propagation delay. However, all known low-k dielectrics exhibit low thermal conductivities, which complicate heat dissipation in high-power-density chips. Two-dimensional (2D) covalent organic frameworks (COFs) combine immense permanent porosities, which lead to low dielectric permittivities, and periodic layered structures, which grant relatively high thermal conductivities. However, conventional synthetic routes produce 2D COFs that are unsuitable for the evaluation of these properties and integration into devices. Here, we report the fabrication of high-quality COF thin films, which enable thermoreflectance and impedance spectroscopy measurements. These measurements reveal that 2D COFs have high thermal conductivities (1 W m K) with ultra-low dielectric permittivities (k = 1.6). These results show that oriented, layered 2D polymers are promising next-generation dielectric layers and that these molecularly precise materials offer tunable combinations of useful properties.
随着微处理器的特征尺寸不断缩小，低介电常数（low-k）材料对于限制电子串扰、电荷积累和信号传播延迟是必不可少的。然而，所有已知的低k电介质都表现出低导热率，这使得高功率密度芯片中的散热变得复杂。二维（2D）共价有机框架（COF）结合了巨大的永久孔隙率（这导致低介电常数）和周期性层状结构（这赋予相对较高的热导率）。然而，传统的合成路线所产生的二维COF并不适合用于评估这些特性以及集成到器件中。在此，我们报道了高质量COF薄膜的制备，该薄膜能够进行热反射和阻抗谱测量。这些测量结果表明，二维COF具有高导热率（1 W m⁻¹ K⁻¹）和超低介电常数（k = 1.6）。这些结果表明，取向的层状二维聚合物是很有前景的下一代介电层，并且这些分子精确的材料提供了有用特性的可调组合。
