Quadratic Voltage Coefficient Of Capacitance Research Articles

The planar anodic Al2O3-ZrO2 nanocomposite capacitor dielectrics for advanced passive device integration

ABSTRACT The need for integrated passive devices (IPDs) emerges from the increasing consumer demand for electronic product miniaturization. Metal-insulator-metal (MIM) capacitors are vital components of IPD systems. Developing new materials and technologies is essential for advancing capacitor characteristics and co-integrating with other electronic passives. Here we present an innovative electrochemical technology joined with the sputter-deposition of Al and Zr layers to synthesize novel planar nanocomposite metal-oxide dielectrics consisting of ZrO2 nanorods self-embedded into the nanoporous Al2O3 matrix such that its pores are entirely filled with zirconium oxide. The technology is utilized in MIM capacitors characterized by modern surface and interface analysis techniques and electrical measurements. In the 95–480 nm thickness range, the best-achieved MIM device characteristics are the one-layer capacitance density of 112 nF·cm−2, the loss tangent of 4·10−3 at frequencies up to 1 MHz, the leakage current density of 40 pA·cm−2, the breakdown field strength of up to 10 MV·cm−1, the energy density of 100 J·cm−3, the quadratic voltage coefficient of capacitance of 4 ppm·V−2, and the temperature coefficient of capacitance of 480 ppm·K−1 at 293–423 K at 1 MHz. The outstanding performance, stability, and tunable capacitors’ characteristics allow for their application in low-pass filters, coupling/decoupling/bypass circuits, RC oscillators, energy-storage devices, ultrafast charge/discharge units, or high-precision analog-to-digital converters. The capacitor technology based on the non-porous planar anodic-oxide dielectrics complements the electrochemical conception of IPDs that combined, until now, the anodized aluminum interconnection, microresistors, and microinductors, all co-related in one system for use in portable electronic devices.

Bovine Serum Albumin-Based Thin-Film Capacitors for Flexible Electronic Applications

Metal–insulator–metal (MIM) thin-film capacitors having different dielectric layer thicknesses have been fabricated by forming bovine serum albumin (BSA) layers on electrically conductive and optically transparent indium tin oxide (ITO) coated polyethylene terephthalate (PET) substrates by using spin coating technique; the metal contacts at the top surface of BSA films have been deposited via thermal evaporation of gaseous phase aluminum. The capacitance-voltage (CV) measurements reveal the fact that the CV-characteristics of the BSA-based MIM capacitors show variable non-linearity with the change in the thickness of the insulating layer (BSA-layer). The experimentally measured CV-data are fitted with 2nd degree polynomial equations and it has been found that the quadratic voltage coefficient of capacitance (VCC) changes its sign from negative to positive as the thickness of the BSA-layer reduced below 2.0 µm. Finally, successful mechanical flexibility tests, as well as curvature tests have been carried out in order to confirm the possibility of using BSA-based MIM thin-film capacitors in flexible electronic applications in near future.

VCC-α nullification and leakage reduction in Pt/Ba0.5Sr0.5TiO3/Pt thin-film capacitor by MgO barrier and PDA for energy storage application

A critical performance parameter of thin-film metal–insulator–metal capacitors when used for energy storage application is leakage current. Introduction of another insulator barrier layer at metal–insulator interface having low electron affinity enhances leakage current performance. The probability of deterioration in capacitance is higher while enhancing leakage performance by barrier layer establishment. The effects of Pt-Ba0.5Sr0.5TiO3 (BST) interface barrier layer and post deposition annealing (PDA) on voltage coefficient of capacitance and leakage current density in Pt/Ba0.5Sr0.5TiO3/Pt thin-film capacitor are reported in this paper. The capacitance measurement is done at low frequency as it meant for energy storage. It is observed that PDA of Pt/MgO/Ba0.5Sr0.5TiO3/MgO/Pt thin-film capacitor at 700 0C in O2 gas environment for 30 min nullifies quadratic voltage coefficient of capacitance (VCC-α). The VCC-α obtained for as-deposited capacitor is −34408 ppm V−2 while that of capacitor annealed at 700 0C is 4.88 ppm V−2 which is the least VCC-α ever reported. A gradual leakage current performance enhancement is observed while increasing annealing temperature and a very low leakage current density of 48 nA cm−2 is observed when annealed at 700 0C. The diffraction peaks in XRD pattern of capacitor annealed at 700 0C indicate good crystallinity achieved in Pt, Ba0.5Sr0.5TiO3 and MgO layers due to high-temperature PDA process. This substantiates the best leakage current characteristics in Pt/MgO/Ba0.5Sr0.5TiO3/MgO/Pt thin-film capacitor annealed at 700 0C than as-deposited capacitor and capacitor annealed at lower temperatures. Further we observed an energy band gap enhancement of 0.055 eV in every 100 0C rise in temperature from the UV–Vis NIR spectroscopy. This continuous energy band gap enhancement while increasing annealing temperature also justifies the reduction in leakage current density at high PDA temperature.

High-Performance MIM Capacitors for a Secondary Power Supply Application.

Microstructure is important to the development of energy devices with high performance. In this work, a three-dimensional Si-based metal-insulator-metal (MIM) capacitor has been reported, which is fabricated by microelectromechanical systems (MEMS) technology. Area enlargement is achieved by forming deep trenches in a silicon substrate using the deep reactive ion etching method. The results indicate that an area of 2.45 × 103 mm2 can be realized in the deep trench structure with a high aspect ratio of 30:1. Subsequently, a dielectric Al2O3 layer and electrode W/TiN layers are deposited by atomic layer deposition. The obtained capacitor has superior performance, such as a high breakdown voltage (34.1 V), a moderate energy density (≥1.23 mJ/cm2) per unit planar area, a high breakdown electric field (6.1 ± 0.1 MV/cm), a low leakage current (10−7 A/cm2 at 22.5 V), and a low quadratic voltage coefficient of capacitance (VCC) (≤63.1 ppm/V2). In addition, the device’s performance has been theoretically examined. The results show that the high energy supply and small leakage current can be attributed to the Poole–Frenkel emission in the high-field region and the trap-assisted tunneling in the low-field region. The reported capacitor has potential application as a secondary power supply.

Study of electrical properties of hafnium oxide thin film based metal–insulator–metal capacitors: pre and post metallic annealing

Metal–insulator–metal (MIM) capacitors having hafnium oxide (HfO2) high-κ dielectric thin film were fabricated and subsequently studied for their electrical and micro-structural properties. The MIM capacitors were found to possess low leakage current density of about 2.7 × 10−9 A/cm2 at −1 V, high capacitance density of about 18.1 fF/μm2 at 0 V, 1 MHz and improved quadratic voltage coefficient of capacitance (VCC) of about 120 ppm/V2 at 1 MHz. The electrical properties of MIM capacitors are found to be governed by Frenkel–Poole mechanism at low and intermediate fields ( 1500 kV/cm). The dielectric thin films have amorphous structure which has been correlated with the electrical properties of MIM capacitors. The HfO2 thin film possess good micro-structural properties in term of low roughness, which is in agreement with the obtained electrical properties of thin film based MIM capacitors. Further, post metallic annealing of MIM capacitors results in decrease in leakage current density to ~5.1 × 10−10 A/cm2 at −1 V, increase in capacitance density to ~23.1 fF/μm2 at 0 V, 1 MHz and improvement in quadratic VCC to reach a value of ~95 ppm/V2 at 1 MHz. The electrical characteristics of as-fabricated and annealed MIM capacitors are in accordance with the International Technology Roadmap for Semiconductor 2013 guidelines. The obtained electrical properties suggest the possible use of MIM capacitors in analog/mixed-signal applications.

Nanostructured Anodic Multilayer Dielectric Stacked Metal-Insulator-Metal Capacitors.

This paper presents the fabrication of Al2O3/TiO2/Al2O3 metal-insulator-metal (MIM) capacitor using anodization technique. High capacitance density of > 3.5 fF/μm2, low quadratic voltage coefficient of capacitance of < 115 ppm/V2 and a low leakage current density of 4.457 x 10(-11) A/cm2 at 3 V are achieved which are suitable for analog and mixed signal applications. We found that the anodization voltage played a major role in electrical and structural properties of the thin film. This work suggests that the anodization method can offer crystalline multilayer dielectric stack required for high performance MIM capacitor.

Voltage linearity modulation and polarity dependent conduction in metal-insulator-metal capacitors with atomic-layer-deposited Al2O3/ZrO2/SiO2 nano-stacks

Excellent voltage linearity of metal-insulator-metal (MIM) capacitors is highly required for next generation radio frequency integration circuits. In this work, employing atomic layer deposition technique, we demonstrated how the voltage linearity of MIM capacitors was modulated by adding different thickness of SiO2 layer to the nano-stack of Al2O3/ZrO2. It was found that the quadratic voltage coefficient of capacitance (α) can be effectively reduced from 1279 to −75 ppm/V2 with increasing the thickness of SiO2 from zero to 4 nm, which is more powerful than increasing the thickness of ZrO2 in the Al2O3/ZrO2 stack. This is attributed to counteraction between the positive α for Al2O3/ZrO2 and the negative one for SiO2 in the MIM capacitors with Al2O3/ZrO2/SiO2 stacks. Interestingly, voltage-polarity dependent conduction behaviors in the MIM capacitors were observed. For electron bottom-injection, the addition of SiO2 obviously suppressed the leakage current; however, it abnormally increased the leakage current for electron top-injection. These are ascribed to the co-existence of shallow and deep traps in ZrO2, and the former is in favor of the field-assisted tunnelling conduction and the latter contributes to the trap-assisted tunnelling process. The above findings will be beneficial to device design and process optimization for high performance MIM capacitors.

Plasma Enhanced Atomic Layer Deposition of Al&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt;/SiO&lt;sub&gt;2&lt;/sub&gt; MIM Capacitors

Metal-insulator-insulator-metal (MIIM) capacitors with bilayers of Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> and SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> are deposited at 200 °C via plasma enhanced atomic layer deposition. Employing the cancelling effect between the positive quadratic voltage coefficient of capacitance (αVCC) of Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> and the negative αVCC of SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> , devices are made that simultaneously meet the International Technology Roadmap for Semiconductors 2020 projections for capacitance density, leakage current density, and voltage nonlinearity. Optimized bilayer Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> /SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> MIIM capacitors exhibit a capacitance density of 10.1 fF/μm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , a leakage current density of 6.8 nA/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> at 1 V, and a minimized αVCC of -20 ppm/V <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> .

Structural, chemical and electrical properties of ALD‐grown HfxAl1–xOy thin films for MIM capacitors

In this paper atomic‐layer deposition (ALD) HfxAl1–xOy thin films with a wide range of metal components concentrations (x = 0.2−0.8) for metal–insulator–metal (MIM) capacitors were investigated with emphasis on the chemical properties and phase composition. It was shown by X‐ray diffraction (XRD) that all films are amorphous. X‐ray photoelectron spectroscopy (XPS) revealed the same energy position with respect to the valence‐band maximum of Al2p and Hf4f lines and a continuous shift of O1s and O‐KLL lines toward the higher binding energy (0.45 and 2.2 eV, respectively) with increase of Al content. Both the shape and position of O1s and O‐KLL lines indicated the inability to deconvolute it on sublines related to the binary oxides. The calculated modified Auger parameter indicated the change of the ionicity of the bonding in HfxAl1–xOy films with change of the composition. Thus, it was proposed that HfxAl1–xOy films in all the studied composition range represent amorphous solid solutions. The continuous change of energy bandgap measured by reflected electron energy loss spectroscopy (REELS) from ∼6.5 eV for Al2O3 to ∼5.4 eV for HfO2 and XRD data do not contradict this assumption. Correlation between structural properties of HfxAl1–xOy films and electrical properties of MIM capacitors based on them was also shown, that is, continuous change in capacitance density (from 3.1 to 7.4fF/µm2), leakage current density and quadratic voltage coefficient of capacitance with composition change was observed.

Increased Multilayer Fabrication and RF Characterization of a High-Density Stacked MIM Capacitor Based on Selective Etching

This paper presents the fabrication and characterization of a high-density multilayer stacked metal–insulator–metal (MIM) capacitor based on a novel process of depositing the MIM multilayer on pillars followed by polishing and selective etching steps to form a stacked capacitor with merely three photolithography steps. In this paper, the pillars were made of glass to prevent substrate loss, whereas an oxide–nitride–oxide dielectric was employed for lower leakage, better voltage/frequency linearity, and better stress compensation. MIM capacitors with six dielectric layers were successfully fabricated, yielding capacitance density of 3.8 fF/ <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="TeX">\(\mu \) </tex-math></inline-formula> m <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="TeX">\(^{2}\) </tex-math></inline-formula> , maximum capacitance of 2.47 nF, and linear and quadratic voltage coefficients of capacitance below 21.2 ppm/V and 2.31 ppm/V <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="TeX">\(^{2}\) </tex-math></inline-formula> . The impedance was measured from 40 Hz to 3 GHz, and characterized by an analytically derived equivalent circuit model to verify the radio frequency applicability. The multilayer stacking-induced plate resistance mismatch and its effect on the equivalent series resistance (ESR) and effective capacitance was also investigated, which can be counteracted by a corrected metal thickness design. A low ESR of 800 m <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="TeX">\(\Omega \) </tex-math></inline-formula> was achieved, whereas the self-resonance frequency was <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="TeX">\(&gt;760\) </tex-math></inline-formula> MHz, successfully demonstrating the feasibility of this method to scale up capacitance densities for high-quality-factor, high-frequency, and large-value MIM capacitors.

Substrate Biasing Effect on the Physical Properties of Reactive RF-Magnetron-Sputtered Aluminum Oxide Dielectric Films on ITO Glasses

High dielectric constant (high-k) Al2O3 thin films were prepared on ITO glasses by reactive RF-magnetron sputtering at room temperature. The effect of substrate bias on the subband structural, morphological, electrode/Al2O3 interfacial and electrical properties of the Al2O3 films is systematically investigated. An optical method based on spectroscopic ellipsometry measurement and modeling is adopted to probe the subband electronic structure, which facilitates us to vividly understand the band-tail and deep-level (4.8-5.0 eV above the valence band maximum) trap states. Well-selected substrate biases can suppress both the trap states due to promoted migration of sputtered particles, which optimizes the leakage current density, breakdown strength, and quadratic voltage coefficient of capacitance. Moreover, high porosity in the unbiased Al2O3 film is considered to induce the absorption of atmospheric moisture and the consequent occurrence of electrolysis reactions at electrode/Al2O3 interface, as a result ruining the electrical properties.

MIM Capacitors Based on ${\rm ZrTiO}_{\rm x}/{\rm BaZr}_{\rm y}{\rm Ti}_{\rm 1-y}{\rm O}_{3}$ Featuring Record-Low VCC and Excellent Reliability

Perovskite-based BaZryTi1-yO3 (BZTO) (y=0.6) with partial crystallization has been found to possess a rather high- κ value of 48.6 and positive quadratic voltage coefficient of capacitance (VCC). Through stacking BZTO and ZrTiOx as laminate dielectric, metal-insulator-metal capacitors using VCC canceling effect advance frontiers by exhibiting a record-low VCC of 14 ppm/V2 at the capacitance of 13.4 fF/μm2, low dielectric loss tangent , and low leakage current of 7.5×10-9 A/cm2 at -1 V. With constant voltage stress at 2.5 V for 1000 s, degradation in leakage current is observed. In addition, excellent reliability of 0.89% capacitance change against stress up to a projected of 10 years is also achieved. The aforementioned characteristics not only compare favorably to other high- κ-based dielectrics, most importantly, but also these results meet ITRS requirements set by 2024.

Nanostructured Bilayer Anodic TiO&lt;SUB&gt;2&lt;/SUB&gt;/Al&lt;SUB&gt;2&lt;/SUB&gt;O&lt;SUB&gt;3&lt;/SUB&gt; Metal-Insulator-Metal Capacitor

This paper presents the fabrication of high performance bilayer TiO2/Al2O3 Metal-Insulator-Metal capacitor using anodization technique. A high capacitance density of 7 fF/microm2, low quadratic voltage coefficient of capacitance of 150 ppm/V2 and a low leakage current density of 9.1 nA/cm2 at 3 V are achieved which are suitable for Analog and Mixed signal applications. The influence of anodization voltage on structural and electrical properties of dielectric stack is studied in detail. At higher anodization voltages, we have observed the transformation of amorphous to crystalline state of TiO2/Al2O3 and improvement of electrical properties.

Improved Leakage and Reliability for ${\rm ZrLaO}_{x}/{\rm ZrTiO}_{x}/{\rm ZrLaO}_{x}$-Based MIM Capacitors by Plasma Nitridation

In this letter, ZrLaO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> /ZrTiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> /ZrLaO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> laminate is employed as the platform for investigating the effects of plasma nitridation on the electrical performance and reliability of metal-insulator-metal capacitors. After plasma nitridation of ZrTiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> , the capacitance density and quadratic voltage coefficient of capacitance (VCC-α) degraded slightly to 14.38 fF/μm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> and 68 ppm/V <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . These results meet the International Technology Roadmap for Semiconductors requirements for implementation in 2020. The major benefits of plasma nitridation are the enhanced performance of the electrical characteristics and reliability. The process reduces leakage current by a factor of 32.8, and improves stress-induced leakage current by a factor of 10.6. In addition, near frequency-independent capacitance is achieved after stressing at 2.5 V for 1000 s, and a desirable reliability of 0.27% capacitance change after a 10-year operation under 2.5-V stress is attained. These results suggest that nitrided ZrTiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> enables ZrLaO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> /ZrTiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> /ZrLaO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> laminate to be a candidate for use in advanced circuit applications.

Performance and Reliability of ${\rm Gd}_{2}{\rm O}_{3}$ and Stacked ${\rm Gd}_{2}{\rm O}_{3}\hbox{-}{\rm Eu}_{2}{\rm O}_{3}$ Metal-Insulator-Metal Capacitors

Gd2O3-based metal-insulator-metal capacitors have been characterized with single layer (Gd2O3) and bilayer (Gd2O3/Eu2O3 and Eu2O3/Gd2O3) stacks for analog and DRAM applications. Although single layer Gd2O3 capacitors provide highest capacitance density (15 fF/μm2), they suffer from high leakage current density, poor capacitance density-voltage linearity, and reliability. The stacked dielectrics help to reduce leakage current density (1.2×10-5 A/cm2 and 2.7 × 10-5 A/cm2 for Gd2O3/Eu2O3 and Eu2O3/Gd2O3, respectively, at -1 V), improve quadratic voltage coefficient of capacitance (331 ppm/V2 and 374 ppm/V2 for Gd2O3/Eu2O3 and Eu2O3/Gd2O3, respectively, at 1 MHz), and improve reliability, with a marginal reduction in capacitance density. This is attributed to lower trap heights as determined from Poole-Frenkel conduction mechanism, and lower defect density as determined from electrode polarization model.

Reactively sputtered HfO2 and Ba(Zr0.2Ti0.8)O3–HfO2 dielectrics for metal–insulator–metal capacitor applications

Reactively sputtered HfO2 and Ba(Zr0.2Ti0.8)O3 (BZT)-HfO2 dielectrics have been compared for high density metal-insulator-metal (MIM) capacitors, which are required for next generation radio frequency and analog/mixed-signal integrated circuits. Our experimental results indicate that the incorporation of BZT into HfO2 can increase the dielectric constant of the insulator, reduce significantly the quadratic voltage coefficient of capacitance (@a), and improve the uniformity of @a. Furthermore, the conduction mechanisms of the capacitors with HfO2 and BZT-HfO2 insulators have been investigated, revealing that the Schottky emission is dominated in both capacitors, and the Schottky barrier under no electric field is extrapolated to be 0.54eV for the MIM capacitor with BZT-HfO2.

$\hbox{ZrLaO}_{x}\hbox{/ZrTiO}_{x}\hbox{/ZrLaO}_{x}$ Laminate as Insulator for MIM Capacitors With High Capacitance Density and Low Quadratic Voltage Coefficient Using Canceling Effect

Metal-insulator-metal (MIM) capacitors with ZrLaO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> /ZrTiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> /ZrLaO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> laminate as the insulator were explored in this work. Single ZrTiOx dielectric was found to have a negative quadratic voltage coefficient of capacitance (VCC-α) with a high κ value of 22.5. By integrating this dielectric with ZrLaOx which provides a positive VCC-α and a high κ value of 25.8, the “canceling effect” of VCC-α can be achieved while a high capacitance density can be maintained. MIM capacitors with the laminated structure display desirable characteristics in terms of a capacitance density of 14.6 fF/μm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , a low VCC-α of 33 ppm/V <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , negligible frequency dispersion, and satisfactory leakage current of 1.6 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-6</sup> A/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> at -1.5 V. These results also well meet the International Technology Roadmap for Semiconductors requirement set for 2020.

Flexible metal–insulator–metal capacitors on polyethylene terephthalate plastic substrates

Realization of flexible electronic devices on polyethylene terephthalate flexible plastic substrates is reported. Metal–insulator–metal capacitors have been fabricated using radio frequency sputtered deposited thin films of Nb2O5 on the flexible substrate. Good electrical characteristics have been obtained in terms of quadratic voltage coefficient of capacitance, high capacitance density (∼ 11 fF µm−2), high dielectric constant (∼37) and low dissipation factor (<0.1). Besides, in repetitive bending test, the devices show excellent electrical stability and high mechanical flexibility due to the high ductility of niobium and low-temperature processing used in this study.

Effect of Nitrogen Passivation on the Performance of MIM Capacitors With a Crystalline- $\hbox{TiO}_{2}/\hbox{SiO}_{2}$ Stacked Insulator

TiO2/SiO2 stacked dielectric-based metal-insulator-metal capacitors with different thermal and nitrogen plasma treatments (NPTs) were explored in this letter. As the TiO2 dielectric crystallizes from amorphous phase after a thermal treatment, capacitance density increasing from 7.7 to 11.9 fF/m2 was obtained at the price of aggravating leakage current and wider distribution in device characteristics. With NPT to well passivate grain-boundary-related defects in the crystalline TiO2 film, devices still keep a satisfactory capacitance level of 11.2 fF/μm2 while exhibiting suppressed leakage current by a factor of 53, a lower quadratic voltage coefficient of capacitance (VCC-α) of 30 ppm/V2, near frequency dispersion-free capacitance, a better temperature coefficient of capacitance of 82 ppm/°C, and more controllable device uniformity. The mechanism for the improved electrical characteristics was further confirmed by atomic force microscope. These results suggest that NPT paves a new avenue to further advance the performance of crystalline dielectric-based devices.

Structural and Electrical Characteristics of $ \hbox{Lu}_{2}\hbox{O}_{3}$ Dielectric Embedded MIM Capacitors for Analog IC Applications

In this study, we develop a high-performance metal-insulator-metal (MIM) capacitor using a high- <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">k</i> Lu <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> amorphous film for radio-frequency and mixed-signal applications. The Ni/ Lu <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> /TaN capacitor exhibited a high capacitance density, a low leakage-current density, and a relatively low quadratic voltage coefficient of capacitance. The leakage current at the low electric field (<; 1.4 MV/cm) was dominated by the Schottky emission, whereas the Poole-Frenkel effect plays in the high electric field. In addition, the effects of constant voltage stress on leakage current and voltage linearity were comprehensively investigated, and excellent device reliability was also demonstrated. The Ni/ Lu <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> /TaN MIM capacitor appears to be very promising for future IC technologies.