Hafnium Oxide/Graphene/Hafnium Oxide-Stacked Nanostructures as Resistive Switching Media

Abstract

Thin HfO2 films were grown by atomic layer deposition on chemical vapor-deposited large-area graphene. The graphene was transferred, prior to the deposition of the HfO2 overlayer, to the HfO2 bottom dielectric layer pregrown on the Si/TiN substrate. Either HfCl4 or Hf­[N­(CH3)­(C2H5)]4 was used as the metal precursor for the bottom layer. The O2 plasma-assisted process was applied for growing HfO2 from Hf­[N­(CH3)­(C2H5)]4 also on the top of graphene. To improve graphene transfer, the effects of the surface pretreatments of the as-grown and aged Si/TiN/HfO2 substrates were studied and compared. The graphene layer retained its integrity after the plasma processes. Studies on resistive switching on HfO2-graphene-HfO2 nanostructures revealed that the operational voltage ranges in the graphene-HfO2 stacks were modified together with the ratios between high- and low-resistance states.

Nanoscale-Thick Thin Films of High-Density HfO2 for Bulk-like Optical Responses

“…14,17,18 Additionally, with such appealing electronic and optical properties, HfO 2 has been the material of choice for the design and development of multilayered nanoscale thin-film devices for memory applications. [9][10][11][12]19 Integrating HfO 2 with two-dimensional and layered materials, such as graphene, has likewise been of interest to realize advanced memory devices on flexible substrates. 9 Furthermore, the recent discovery of ferroelectric properties in nanoscale thin films of silicon-doped HfO 2 is representative of promising electronic and optoelectronic applications in intrinsic and doped nanoscale-thick thin-film systems (i.e., <500 nm).…”

“…[9][10][11][12]19 Integrating HfO 2 with two-dimensional and layered materials, such as graphene, has likewise been of interest to realize advanced memory devices on flexible substrates. 9 Furthermore, the recent discovery of ferroelectric properties in nanoscale thin films of silicon-doped HfO 2 is representative of promising electronic and optoelectronic applications in intrinsic and doped nanoscale-thick thin-film systems (i.e., <500 nm). 9 Such nanomaterial electrical and optical properties are predicted to be further tailorable via controlled dopant incorporation (e.g., with Ti or Zr).…”

“…9 Furthermore, the recent discovery of ferroelectric properties in nanoscale thin films of silicon-doped HfO 2 is representative of promising electronic and optoelectronic applications in intrinsic and doped nanoscale-thick thin-film systems (i.e., <500 nm). 9 Such nanomaterial electrical and optical properties are predicted to be further tailorable via controlled dopant incorporation (e.g., with Ti or Zr). 20 Despite these property and performance advantages, the optical and structural properties of thin-film HfO mechanism (i.e., method-dependent thermal activation energy, cluster energy, migration energy, chemical stoichiometry of interface boundaries, and so forth).…”

“…HfO 2 is a refractory material with a high dielectric constant and wide band gap and exhibits considerable thermal and chemical stability. − As such, the high refractive index, broadband transparency, low spectral absorption, and thermochemical stability of HfO 2 present an appealing material choice for high-performance low-dimensional or nanoscale energy, electronic (integrated circuit technology), and ultrathin-film optical device applications. − HfO 2 has also been considered an alternative to SiO 2 in microelectronic devices (e.g., as a dielectric layer gate oxide in metal-oxide semiconductor devices) due to high refractive indices in the ultraviolet and visible wavelength regimes and lower electron tunneling effects. ,, Additionally, with such appealing electronic and optical properties, HfO 2 has been the material of choice for the design and development of multilayered nanoscale thin-film devices for memory applications. − , Integrating HfO 2 with two-dimensional and layered materials, such as graphene, has likewise been of interest to realize advanced memory devices on flexible substrates . Furthermore, the recent discovery of ferroelectric properties in nanoscale thin films of silicon-doped HfO 2 is representative of promising electronic and optoelectronic applications in intrinsic and doped nanoscale-thick thin-film systems (i.e., <500 nm) . Such nanomaterial electrical and optical properties are predicted to be further tailorable via controlled dopant incorporation (e.g., with Ti or Zr) .…”

Estudio de la conmutación resistiva a partir de la caracterización eléctrica de estructuras MIM

“…3.27: Esquema del proceso de fabricación de las muestras indicando los diferentes tratamientos efectuados a cada muestra para depositar el grafeno. Imagen publicada en [227].…”