Toward miniaturizing microelectronics using covalent organic framework dielectric

As miniaturization of microelectronics reaches sub-10 nm scale, signal crosstalk and parasitic resistive-capacitive delay significantly limit device performance. While low dielectric constant (low-κ) dielectrics are widely recognized to address such issue, their poor thermal conductivity impedes heat management. Recently, scientists from Northwestern University Virginia demonstrated the fabrication pristine covalent organic framework (COF) thin films as a thermally conducting low-κ dielectric. Specifically, reported COF-5 film complements value (κ = 1.6) with high (1 W m−1 K−1), offering promising adaptations in power density. Driven by ever-growing demand market sophisticated yet slick electronic devices, microelectronic an unprecedented level, where chips developed utilized maximize density components per unit area. At however, insulating material that separates conductive supports chip mechanical integrity can undergo charge polarization driven surrounding electric field. In turn, this phenomenon hampers performance causing response delay, crosstalk, increased consumption.1Volksen W. Miller R.D. Dubois G. Low materials.Chem. Rev. 2010; 110: 56-110Google Scholar Therefore, pointed Semiconductor Industry Association, incorporation materials (i.e., strongly resist phenomenon) is requisite mitigate capacitance effect, minimizing costly loss.2IEEEInternational Roadmap for Devices Systems (IRDS).https://irds.ieee.org/Date: 2017Google Several restrictions selection developing novel dielectrics. First, require sufficient ensure stable reliable electrical isolation. Fabrication scaling another important consideration enable preparation without particle contamination. addition, interlayer adhesion processability crucial facile integration.1Volksen Scholar,3Shao P. Li J. Chen F. Ma L. Q. Zhang M. et al.Flexible frameworks ultralow constants under humidity.Angew. Chem. Int. Ed. 2018; 57: 16501-16505Google Noting stability ceramics, they represent strong candidates inorganic However, brittleness flexibility complicate subsequent processing.3Shao With air having lowest κ 1), effective be lowered incorporating structural porosity. Nevertheless, consistent pore size uniform distribution necessary maintain adequate strength. To end, crystalline porous (COFs) metal [MOFs]) regarded systems Versatility processing, tunability, periodical alignment several benefits utilizing COF/MOF establishing new materials. COF offer better resistance toward humidity, alongside lower values lesser polarizability.3Shao adaptation has thus far been limited. An reason failure existing methods generating uniformly oriented wafer-scale deposited This turn limits thorough accurate assessment suitability dielectric.4Rodríguez-San-Miguel D. Zamora Processing frameworks: ingredient succeed.Chem. Soc. 2019; 48: 4375-4386Google Dichtel, Hopkins, coworkers showcased fine dielectric, added benefit satisfactory (Figure 1).5Evans A.M. Giri A. Sangwan V.K. Xun S. Bartnof Torres-Castanedo C.G. Balch H.B. Rahn M.S. Bradshaw N.P. Vitaku E. al.Thermally ultra-low-k layers based on two-dimensional frameworks.Nat. Mater. 2021; https://doi.org/10.1038/s41563-021-00934-3Google Developing previous graphene-templated solvothermal assembly,6Colson J.W. Woll A.R. Mukherjee Levendorf M.P. Spitler E.L. Shields V.B. Spencer M.G. Park Dichtel W.R. Oriented 2D single-layer graphene.Science. 2011; 332: 228-231Google authors implemented templated colloidal polymerization approach grow five boronate ester-linked (<75 thickness) single layer graphene or molybdenum disulfide substrate <5 surface roughness. Their detailed characterization studies indicated COD were arranged parallel onto substrates. They then concluded preparing provides synthetic control crystallinity, roughness, orientation when compared other methods. Supported density-functional theory (DFT) calculation predicting < 2 all prepared films, focused showed experimentally ∼6 pF robust 1.62 across varied humidity temperatures.5Evans impedance measurements confirmed could serve Moreover, cross-plane optical emission feature was attributed highly film, corroborating importance approach. Satisfied its property, studied films. Thus far, permittivity associated conductivity, posing significant management concern especially devices density.7Hopkins P.E. Kaehr B. Piekos E.S. Dunphy Brinker C.J. Minimum considerations aerogel films.J. Appl. Phys. 2012; 111: 113532Google By performing time- frequency-domain thermoreflectance studies, achieved 1 K−1 film. folds higher than previously polymers (generally <0.3 K−1). molecular dynamics simulations predicted anisotropic in-plane ratio 3.4 film.5Evans The improved structure well-interfaced stacking enhancing dissipative coating microelectronics. summary, described synthesis method synthesize additional conductivity. thoroughly properties including current leakage well impacts temperature, frequency constant. Further expected understand (e.g., elastic modulus bulk modulus) ensuring long-term minimal deterioration integration.8Eslava Esconjauregui Yang Vanstreels K. Baklanov M.R. Saiz Metal-organic ZIF-8 microelectronics.Chem. 2013; 25: 27-33Google mentioned, introduction guests worthy investment alter promote thermo-mechanical Thus, work paves way employing versatility nature warrant applications MOF formulations. It foreseeable will draw wide implementation fields, filtration treatments, sensors, catalysis, soon open innovative utilizations.9Zhang C. Wu B.-H. M.-Q. Wang Z. Xu Z.-K. Ultrathin metal/covalent-organic membranes towards ultimate separation.Chem. 3811-3841Google Scholar, 10Qian Zhou Qiao X. Teo W.L. al.Linkage engineering harnessing supramolecular interactions fabricate hydrazone-linked platforms advanced catalysis.J. Am. 2020; 142: 18138-18149Google acknowledge Ministry Education Singapore Academic Research Funds ( MOE-MOET2EP10120-0003 ).