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 (HfO2) was selected as the dielectric. After a low-temperature annealing process, the deposited nanoparticle (NP)-based ink of HfO2 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 HfO2 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 HfO2 NPs work properly within the ITRS 2016 roadmap requirements.

Flexible inkjet printed high-k HfO2-based MIM capacitors

This work highlights the influence of the oxygen affinity of the metal electrodes used in high-k metal-insulator-metal capacitors. Several metallic electrodes are tested in order to investigate the role of the metal work function, and the role of the electrode oxygen-affinity in nonlinear behavior of HfO2 and BaTiO3 capacitors. It is shown that the magnitude of the quadratic coefficient of nonlinearity is better explained by the electrode oxygen-affinity rather than by its work function. It is thought that electrode oxidation increases the number of oxygen vacancies at the electrode/dielectric interface, and so increases the magnitude of nonlinearity.

/pdf/electrode-oxygen-affinity-influence-on-voltage-1q3dnqodnm.pdf

Electrode oxygen-affinity influence on voltage nonlinearities in high-k metal-insulator-metal capacitors

TEM study of 〈110〉-type 35.26° dislocations specially induced by polishing of SrTiO3 single crystals

High-dielectric constant (high-k) gate oxides and low-dielectric constant (low-k) interlayer dielectrics (ILD) have dominated the nanoelectronic materials research scene over the past two decades, but they have recently reached a state of maturity and perhaps the limits of their scaling. Based on this, there is a need for a systematic review summarizing not only the historic research and achievements on high-k and low-k dielectrics, but also emerging device applications as well as an outlook of future challenges.We begin by first reviewing the factors that drove the emergence of low-k and high-k materials in nanoelectronics as ILD and gate dielectric materials, respectively, and the challenges and limits these materials ultimately approached in terms of permittivity scaling.We then illustrate that gate dielectric and ILD applications represent just a small fraction of the numerous dielectrics utilized in present day nanoelectronic products where permittivity scaling is now being increasingly demanded for materials such as dielectric spacers, trench isolation, and etch stopping layers. We conclude by examining the numerous new applications for dielectric materials that are emerging as the semiconductor industry transitions to novel patterning schemes, prepares for life post CMOS scaling, and explores ways to natively embed device functionality in the metal interconnect. For the former, we specifically examine the “colorful”requirements for the various enabling dielectric hard mask and spacer materials utilized in pitch division-multi-pattern processes and then discuss the role that selective area deposition of dielectrics and metals could play in reducing the complexity of such patterning processes. For the latter, we review the use of both high-k and low-k dielectrics in various metal-insulator-metal (MIM) structures as Fermi level de-pinning layers, tunnel diodes, and back-end-of-line (BEOL) compatible capacitive and resistive switching random access memory (ReRAM) elements.We further examine how dielectrics can hinder or aid new forms of computing such as quantum and neuromorphic in reaching their full potential. In conclusion, we find that while the field of dielectrics has a long history, it remains vibrant with numerous exciting new and old research vectors awaiting further exploration.© 2019 The Electrochemical Society.

https://iopscience.iop.org/article/10.1149/2.0161910jss/pdf

Review—Beyond the highs and lows: A perspective on the future of dielectrics research for nanoelectronic devices

First-principles investigation of structural, electronic, optical and thermal properties of Zinc doped SrTiO3

Future integration of metal-insulator-metal capacitors requires devices with high capacitance density and low quadratic voltage coefficient of capacitance (α). A major problem is that the increase in capacitance density is usually accompanied by increased voltage nonlinearities. By combining two high-k materials with opposite α, it is demonstrated that it is possible to obtain capacitors with both high capacitance density and minimal nonlinearity. A SrTiO3/ZrO2 bilayer was used to elaborate capacitors displaying a voltage coefficient of −60 ppm/V2 associated with a density of 11.5 fF/μm2. These devices constitute excellent candidates for the next generation of metal-insulator-metal capacitors.

/pdf/high-performance-metal-insulator-metal-capacitor-using-a-24fkcjsyjq.pdf

High performance metal-insulator-metal capacitor using a SrTiO3/ZrO2 bilayer

Direct bonding has been a major key technology in many fields nowadays. From microelectronic to optoelectronic technologies, it became a technique used for mass production technology in many different applications. Direct bonding of silicon or silicon dioxide is now a well known process. In this article, we explore this technology through the transfer of a crystalline multilayer made of III-V materials (AlGaAs/GaAs) from its native GaAs substrate upon a fused silica substrate (SiO2). The goal of this work is to explore the conception of crystalline Bragg mirrors with low mechanical loss and high optical quality for precision measurement applications. We present the main results obtained for each step of the transfer process. Various experiment such as AFM characterization have been performed on the wafers to probe surface quality. Chemical wet etching with different experimental conditions have been tested to remove the GaAs substrate. We discuss the main challenges of the process, especially the bonding of two rather different materials from the thermo-mechanic point of view. Focus is also made on the chemistry used in the wet etching part to have a selective etching between GaAs and AlGaAs.

https://hal-cea.archives-ouvertes.fr/cea-03735678/file/2022_SPIE_Photonics_Europe_VHUI.pdf

C. Dubarry

Papers

High performance metal-insulator-metal capacitor using a SrTiO3/ZrO2 bilayer

Transfer of an AlGaAs/GaAs crystalline Bragg mirror from a GaAs substrate to a fused silica substrate by direct bonding

Challenges and Solutions for the Fabrication of CMOS-driven Microled Displays