Magnetoresistance Recovery in the Amorphous Dielectric Material SiCOH

The use of a magnetoresistance in the characterization of transport properties in the amorphous low-k dielectric material SiCOH is demonstrated. The double occupancy of charge carriers in trap states within the dielectric material can only exist in spin singlet formation due to Pauli Exclusion. The trap-assisted negative magnetoresistance (MR) in amorphous SiCOH, driven by an applied electric field that results in an observed increase in magnitude of the current in the conduction band is due to singly occupied trap spin-mixing suppression of carriers with the application of an external magnetic field. The material MR decays with time under electrical bias and temperature stress as traps are filled by charge carriers and from space charge accumulation. The MR can be reinstated by the ionization of these traps via the conduction mechanisms of nonthermally activated tunneling and thermal ionization with the assistance of an applied coulombic potential barrier lowering electric field. In this work a direct correlation is shown between a material MR and the trapping, de-trapping, and trap avoidance of singly occupied traps in the transport of charge carriers in the amorphous low-k dielectric material SiCOH (a-SiCOH).

Transition from light diffusion to localization in three-dimensional amorphous dielectric networks near the band edge

Localization of light is the photon analog of electron localization in disordered lattices, for whose discovery Anderson received the Nobel prize in 1977. The question about its existence in open three-dimensional materials has eluded an experimental and full theoretical verification for decades. Here we study numerically electromagnetic vector wave transmittance through realistic digital representations of hyperuniform dielectric networks, a new class of highly correlated but disordered photonic band gap materials. We identify the evanescent decay of the transmitted power in the gap and diffusive transport far from the gap. Near the gap, we find that transport sets off diffusive but, with increasing slab thickness, crosses over gradually to a faster decay, signaling localization. We show that we can describe the transition to localization at the mobility edge using the self-consistent theory of localization based on the concept of a position-dependent diffusion coefficient.

STRUCTURAL AND ELECTROPHYSICALLY PERFECT SILICONSAPPHIRE HETEROPAIRS WITH A HIGH-K INTERLAYER DIELECTRIC

This work investigates the features of the formation of a silicon-sapphire interlayer heterointerface obtained by direct splicing, both with an intermediate amorphous dielectric (Hf, Zr, Al; AlN oxides) and without it. The results of structural and electrophysical studies of these structures are presented.

Solution-processed amorphous yttrium aluminium oxide YAlxOy and aluminum oxide AlxOy, and their functional dielectric properties and performance in thin-film transistors

Yttrium aluminium oxide (YAlxOy) dielectric is accessible using a molecular single-source precursor approach. Processing using deep UV leads to a functional amorphous dielectric with functionality in a thin-film transistor device.

Optothermally Tuned Charge Transfer Plasmons in Au-Ge2Sb2Te5 Core-Shell Assemblies

ABSTRACTTunable plasmonic resonances across the visible and near infrared spectra have provided novel ways to develop next-generation nanophotonic devices. Here, by utilizing optothermally controllable phase-changing material (PCM), we studied highly tunable charge transfer plasmon (CTP) resonance modes. To this end, we have designed a two-member dimer assembly including gold cores and Ge2Sb2Te5 (GST) shells in distant, touching, and overlapping conditions. We successfully demonstrated that toggling between amorphous (dielectric) and crystalline (conductive) phases of GST allows for achieving tunable dipolar and CTP resonances along the near-infrared spectrum. The proposed dimer structures can help forming optothermally controlled devices without further morphological variations in the geometry of the design, and having strong potential for advanced plasmon modulation and fast data routing.

Amorphous Dielectric Thin Films with Extremely Low Mechanical Loss

The ubiquitous low-energy excitations are one of the universal phenomena of amorphous solids. These excitations dominate the acoustic, dielectric, and thermal properties of structurally disordered solids. One exception has been a type of hydrogenated amorphous silicon (a-Si:H) with 1 at.% H. Using low temperature elastic and thermal measurements of electron-beam evap-orated amorphous silicon (a-Si), we show that TLS can be eliminated in this system as the films become denser and more structurally ordered under certain deposition conditions. Our results demonstrate that TLS are not intrinsic to the glassy state but instead reside in low density regions of the amorphous network. This work obviates the role hydrogen was previously thought to play in removing TLS in a-Si:H and favors an ideal four-fold covalently bonded amorphous structure as the cause for the disappearance of TLS. Our result supports the notion that a-Si can be made a “perfect glass” with “crystal-like” properties, thus offering an encouraging opportunity to use it as a simple crystal dielectric alternative in applications, such as in modern quantum devices where TLS are the source of dissipation, decoherence and 1/f noise.