Antianisotropic Growth Enabled Compact MIL-53 Films for Ultralow- k Interconnect Dielectrics

Abstract

The miniaturization of integrated circuits is increasingly limited by parasitic resistance−capacitance (RC) delay. Metal−organic frameworks (MOFs) are promising low-dielectric-constant (low-k) materials, yet simultaneously achieving ultralow k and mechanical robustness remains challenging. Here, we propose an antianisotropic growth strategy to fabricate compact MIL-53(Al) thin films via microwave-assisted hydrothermal conversion of an atomic layer-deposited Al2O3 layer. By combining a metal species modulator to reduce the grain length-to-width ratio with a pH modulator to boost nucleation, this synergistic approach enables nanoscale-controlled growth. The optimized microstructure enhanced the elastic modulus by 45.9% while maintaining an ultralow k of 1.98 at 1 MHz. The breakdown field increased approximately 4-fold, resulting in a projected lifetime of 5.55 years at 1 MV cm−1. The antianisotropic growth strategy enables MOF films to combine ultralow k with robust mechanical properties and reliability, offering a practical strategy for high-performance dielectrics in next-generation interconnect technologies.