Search

A novel vertical architecture for all-printed organic electrochemical transistors, based on poly(3, 4-ethylenedioxythiophene):poly(styrene sulfonate), realized on flexible substrates, is reported. The transistors are manufactured along both faces of plastic or paper substrates and via connections are realized using laser ablation or simple punch through using a pin. Successful modulation of the electric current that flows between the two sides of the substrate is achieved using electrolyte-gating and electrochemical modulation of the electronic charge transport of the bulk of the transistor channel. In addition to this, the transistors are exhibiting fast switching and high ON/OFF current ratios. [ABSTRACT FROM AUTHOR]

A geometrical formulation of a space-time finite-integration (FI) method is studied for application in electromagnetic-wave propagation calculations. Based on the Hodge duality and Lorentzian metric, a modified relation is derived between the incidence matrices of space-time primal and dual grids. A systematic method to construct the Maxwell grid equations on the space-time primal and dual grids is developed. The geometrical formulation is implemented on a simple space-time grid, which is proven equivalent to an explicit time-marching scheme of the space-time FI method. [ABSTRACT FROM AUTHOR]

A simple and stable sub-grid scheme is derived from the space-time finite integration method, where staircase-shaped edges can be used to construct a rectangle-based grid. Comparison with classical sub-grid methods shows that the proposed method suppresses unphysical wave reflection without interpolation of field values for the sub-grid connection. No numerical instability was observed even after 10^\mathrm \mathbf 6 time steps. The proposed method was applied to the computation of a photonic band gap. [ABSTRACT FROM PUBLISHER]

High performance Cu dual-damascene (DD) interconnects without process-induced damages are developed in porous SiOCH stacks with the effective dielectric constant (keff) of 2.95, in which a carbon (C)-rich molecular-pore-stacking (MPS) SiOCH film (k = 2.5) is stacked directly on an oxygen (O)-rich porous SiOCH (k = 2.7) film. The novel etch-stopperless structure is obtained by comprehensive chemistry design of C/O ratios in the SiOCH stack and the etching plasma of an Ar/N2/CF4/O2 gas mixture technique. Large hydrocarbons attached to hexagonal silica backbones in the MPS-SiOCH prevent the Si-CHx bonds from oxidation during O2-plasma ashing, suppressing the C-depleted damage area at the DD sidewall. Combining multiresist mask process with immersion ArF photolithography, strictly controlled Cu DD interconnects with 180-nm pitched lines and 65-nm-diameter vias are obtained successfully, ready for the 300-mm fabrication. [ABSTRACT FROM AUTHOR]

The performance and reliability of Cu/Low-Kappa; damascene interconnects are investigated from the view point of the material interface structure. We are focusing especially on the heteronterfaces between the Cu and the barrier metal BM), as well as between the hard mask `(HM) and the capping barrier dielectrics (CAP) Covered on the Cu interconnects. It is found that the highest via reliabilities of etectromigration (EM) and thermal cycle are established by the barrier-metal-free (BMF) structure without the heterointerface between the Cu and the BM due to the strong Cu-to-Cu connection at the via bottom. The interline time-dependant dielectric breakdown lifetime is improved mostly by using a JIM with the same materials as the CAP layer, referred to as an unified structure, which diminishes the heterointerface between the HM and the CAP. These ideal structures without the material heterointerfaces derive the highest reliability and performance. Structural control of the material heterointerfaces in the actual Cu/low-Kappa; damascene interconnect is crucial for the high reliability and performance. [ABSTRACT FROM AUTHOR]