Metal-Organic Framework ZIF-8 Films As Low-κ Dielectrics in Microelectronics

ZIF-8 films were deposited on silicon wafers and characterized to assess their potential as future insulators (low-κ dielectrics) in microelectronics. Scanning electron microscopy and gas adsorption monitored by spectroscopic ellipsometry confirmed the good coalescence of the crystals, the absence of intergranular voids, and the hydrophobicity of the pores. Mechanical properties were assessed by nanoindentation and tape tests, confirming sufficient rigidity for chip manufacturing processes (elastic modulus >3 GPa) and the good adhesion to the support. The dielectric constant was measured by impedance analysis at different frequencies and temperatures, indicating that κ was only 2.33 (±0.05) at 100 kHz, a result of low polarizability and density in the films. Intensity voltage curves showed that the leakage current was only 10–8 A cm2 at 1 MV cm–1, and the breakdown voltage was above 2 MV cm–1. In conclusion, metal-organic framework ZIF-8 films were experimentally found to be promising candidates as low-κ dielectrics in microelectronic chip devices. This opens a new direction for research into the application of metal-organic frameworks.