Enhanced Dielectric Constant of HfO2 and Al2O3 Thin-Films with Silver Nanoparticles

Abstract

Through an electron beam evaporation process, silver nanoparticles (Ag-nps) were introduced into dielectric thin-films. Silver incorporation into the oxide films resulted in a distribution of insulating Ag-nps at a density of ~10^12 particles/cm^2. For these samples, an enhancement of about two fold in dielectric constant was observed in both Al2O3 and HfO2. We attribute the dielectric constant enhancement to the polarizability of metallic nanoparticles. The dipole moment of the Ag-nps increased the stack dielectric constant in a frequency dependent manner. Because of the inherent relaxation frequency of the Ag-np dipoles and space-charge polarization, the dielectric constant was more strongly enhanced at lower frequencies (down to 100 Hz) relative to higher frequencies (up to 1 MHz). Gate leakage currents remained comparable between the control and nanocomposite samples. The Ag-nps also produced a memory effect. Potential applications of these Ag-np based films in CMOS devices are discussed.

Dielectric metal/metal oxide nanocomposites: modeling response properties at multiple scales

“…One way to increase the permittivity of a dielectric is to add highly polarizable inclusions [3,5]. As with other composites, the properties of the mixed material are potentially tunable.…”

“…In addition, the inclusion of metallic nanoparticles has been shown to increase the permittivities of both polymer and metal oxide (ZnO, Al 2 O 3 , HfO 2 , VO 2 , etc.) thin films [5,6,[8][9][10][11][12][13][14]. The latter combinations show potential for integrating dielectrically-enhanced composites with existing semiconductor technologies.…”

Dielectric metal/metal oxide nanocomposites: modeling response properties at multiple scales

“…One way to increase the permittivity of a dielectric is to add highly polarizable inclusions. [3,5] As with other composites, the properties of the mixed material are potentially tunable. By adjusting the composition, size, and loading of inclusions, materials with desired properties such as static dielectric permittivities, breakdown voltages, and dielectric losses can be fabricated.…”

“…thin films. [5,8,9,10,11,6,12,13,14] The latter combinations show potential for integrating dielectrically-enhanced composites with existing semiconductor technologies.…”

Influence of Ru Dopant on the Dielectric Properties of Zr-doped HfO2 High-k Thin Film

“…higher k values, lower leakage currents, thinner interface layers, and higher amorphous-to-polycrystalline transition temperatures [1][2][3]. It was also reported that adding silver nanoparticles in HfO 2 could increase the k value due to dipole enhancement [4]. In this work, the idea of doping the Zr-doped HfO x (ZrHfO x ) film with Ru is presented and the resulting materials and electrical properties were studied.…”