Flexible inkjet printed high-k HfO2-based MIM capacitorsElectronic supplementary information (ESI) available: Details of device fabrication, XPS HfO2 survey, and C-V curves on different substrates. See DOI: 10.1039/c5tc03307a

• Main Authors: Vescio, G, López-Vidrier, J, Leghrib, R, Cornet, A, Cirera, A
• Format: Journal Article
• Published: 25.02.2016
• ISSN: 2050-7526; 2050-7534
• DOI: 10.1039/c5tc03307a

The soaring global demand for flexible, wearable and transparent devices has created an urgent need for new fabrication technologies that are both cost-competitive and eco-friendly. Printed electronics holds the promise of enabling low-cost, scalable solutions exploiting the ability of innovative materials to be used as processed inks onto a large area substrate. In this article, we demonstrate the direct drop-on-demand inkjet printing technology as a viable method for the fabrication of fully-printed metal-insulator-metal capacitors on a flexible substrate (Kapton®), where the high- k hafnium oxide (HfO 2 ) was selected as the dielectric. After a low-temperature annealing process, the deposited nanoparticle (NP)-based ink of HfO 2 showed high homogeneity and good integrity of the printed thin film by microscopy and spectroscopy studies. The fully-printed capacitors were characterized by field-emission scanning and transmission electron microscopies. X-ray diffraction patterns, as well as Raman scattering and Fourier-transform infrared spectra, revealed the presence of a polycrystalline solid layer, without solvent organic ink remains. The bonding structure of the HfO 2 layer and the interface with the Ag electrode was studied by X-ray photoelectron spectroscopy. The good performance of the thin film was proved by its relative permittivity, k = 12.6, and dielectric loss tangent, tan  δ = 0.0125 at 1 MHz. Finally, the electrical current density-voltage and capacitance-voltage measurements have been studied in the frequency range from 10 kHz to 1 MHz. The obtained results indicate that MIM capacitors based on inkjet-printed flexible HfO 2 NPs work properly within the ITRS 2016 roadmap requirements. The soaring global demand for flexible, wearable and transparent devices has created an urgent need for new fabrication technologies that are both cost-competitive and eco-friendly.