Transparent and flexible capacitors based on nanolaminate Al2O3/TiO2/Al2O3

Abstract

Transparent and flexible capacitors based on nanolaminate Al2O3/TiO2/Al2O3 dielectrics have been fabricated on indium tin oxide-coated polyethylene naphthalate substrates by atomic layer deposition. A capacitance density of 7.8 fF/μm2 at 10 KHz was obtained, corresponding to a dielectric constant of 26.3. Moreover, a low leakage current density of 3.9 × 10−8 A/cm2 at 1 V has been realized. Bending test shows that the capacitors have better performances in concave conditions than in convex conditions. The capacitors exhibit an average optical transmittance of about 70% in visible range and thus open the door for applications in transparent and flexible integrated circuits.

Structural and Dielectric Properties of Subnanometric Laminates of Binary Oxides

“…Also, they are strongly enhanced compared to the values obtained in Al 2 O 3 /TiO 2 laminates, even for those with crystalline TiO 2 . 6,7,9 The figure shows the results of three individual capacitors for each sample (although not all can be distinguished by eye because of their high resemblance) in order to underline the obtained reproducibility. At high frequencies, all samples show the same κ value, corresponding to what would be expected from a series of individual capacitances of TiO 2 and Al 2 O 3 with the employed thickness ratio.…”

“…However, the values of κ that can be reached are at maximum those of the high-κ oxide, resulting in values of up to 8 in amorphous Al 2 O 3 /TiO 2 nanolaminates, 7 20 in the case of crystalline Al 2 O 3 /TiO 2 nanolaminates, 6 or 26 in the case of Al 2 O 3 /TiO 2 /Al 2 O 3 trilayers. 9 If the individual layer thickness is even more reduced into the limit of subnanometer thicknesses, even higher κ values can be observed. Reports on amorphous subnanometric laminates of Al 2 O 3 and TiO 2 show κ ranging up to 10000, 10 comparable to those obtained for complex oxides in a crystalline phase.…”

Maxwell–Wagner Relaxation-Driven High Dielectric Constant in Al2O3/TiO2 Nanolaminates Grown by Pulsed Laser Deposition

“…In this regard, several high- k binary oxides such as HfO 2 ( k ∼ 25), ZrO 2 ( k ∼ 25), and TiO 2 ( k ∼ 40) have been investigated extensively to replace conventional SiO 2. , However, with further scaling down to the nanometer regime, these oxides exhibited higher dielectric losses, unstable interfaces with semiconductor substrates, and high leakage currents, which limit their practical application in modern nanoelectronic devices. , Because a high- k dielectric material along with low leakage and low loss is crucial for further miniaturization of microelectronic components, in recent years, extensive studies have been focused on improving the dielectric properties of these binary high- k oxides either by doping or developing new materials systems such as composites, heterostructures, and nanolaminates (NLs). − Among these, multilayered NLs consisting of alternate ultrathin sublayers of two high- k dielectrics have recently garnered significant attention owing to their superior electrical and dielectric properties, suitable for a wide range of potential applications in next-generation data and energy storage devices, metal-oxide-semiconductor capacitors, and field-effect transistors. − …”

Semiconductor Materials by Ultrasonic Spray Pyrolysis and Their Application in Electronic Devices

“…Applications, such as thin-film transistors (TFTs), sensors, electronic circuits, among others, have been reported [8][9][10]. The results reported by other authors show that the main limitation is the need to use high deposition temperatures to achieve high-quality semiconductor films, since low-temperature deposition may lead to an incomplete pyrolysis of the precursor solutions [11].…”