Increasing emission current from MIM cathodes by using an Ir-Pt-Aumultilayer top electrode

We investigated the effect of the top electrode materials on the electron emission and durability of metal-insulator-metal (MIM) cathodes. The durability is improved when high sublimation-enthalpy material, such as Ir, Mo, or W, are used; however, the emission current, and the transfer ratio, decrease. The material dependence of the transfer ratio is shown to be dominated by the scattering probability of hot electrons in the metal. The scattering probability was estimated from the metal's density-of-states, or more simply, from the number of d-electrons. We found that the multilayer top electrode consisting of Ir, Pt, and Au provides the best top electrode combination for MIM cathodes. The high sublimation-enthalpy Ir layer, which is in contact with the insulator, acts as a barrier metal and improves the durability, whereas the surface Au layer maintains the transfer ratio at a high value. With this top electrode structure, emission current density is increased to 5.8 mA/cm², which is sufficient for field-emission displays. We demonstrated a display consisting of a 30×30-dot MIM cathode-array with the multilayer top electrodes     

Electron-microscopic imaging of single-walled carbon nanotubes grown on silicon and silicon oxide substrates

Direct imaging of single-walled carbon nanotubes (SWNTs) suspended on pillar-patterned Si or SiO2 substrates is investigated using transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The suspended nanotubes are successfully observed by direct TEM imaging and it is seen that they have either individual or bundles of SWNTs. Low energy (< or =2 keV) SEM produces high contrast images of suspended SWNTs. On the contrary, when SWNTs contact a SiO2 substrate, they are imaged using electron-beam induced current. The image brightness depends on the length of SWNTs.     

Planar lightwave integrated circuits with embedded actives for board and substrate level optical signal distribution

This paper explores design options for planar optical interconnections integrated onto boards, discusses fabrication options for both beam turning and embedded interconnections to optoelectronic devices, describes integration processes for creating embedded planar optical interconnections, and discusses measurement results for a number of integration schemes that have been demonstrated by the authors. In the area of optical interconnections with beams coupled to and from the board, the topics covered include integrated metal-coated polymer mirrors and volume holographic gratings for optical beam turning perpendicular to the board. Optical interconnections that utilize active thin film (approximately 1-5 /spl mu/m thick) optoelectronic components embedded in the board are also discussed, using both Si and high temperature FR-4 substrates. Both direct and evanescent coupling of optical signals into and out of the waveguide are discussed using embedded optical lasers and photodetectors.     

Vectorial finite-element method without spurious solutions for dielectric waveguide problems

A new vectorial finite-element method for the analysis of dielectric waveguide problems is formulated in terms of all three components of the magnetic field H. In this approach, the relation div H = 0 is satisfied and the spurious non-physical solutions do not appear.     

Threshold for Millimeter-Wave (60 GHz)-Induced Ocular Injury

Journal of Infrared, Millimeter, and Terahertz Waves - Millimeter waves (MMW) absorbed by skin or cornea may induce damage by heat. We have developed a 60&nbsp;GHz MMW exposure-induced eye...     

Simultaneous estimation of echo path and channel responses usingfull-duplex transmitted training data sequences

To reduce the system initialization time in high-speed full-duplex data transmission over two-wire lines, we propose an efficient full-duplex fast training algorithm which can simultaneously estimate the impulse responses of echo paths and channels at both ends. Two mutually orthogonal periodic sequences are designed and used to co-estimate the near echo, the far echo with bulk delay, and the channel response. The new algorithm can reduce the tap-setting time to half of that required by the traditional half-duplex fast training schemes. The effects of channel noise and symbol rate offset between two ends are examined in terms of both mean-square error (MSE) and signal-to-noise ratio (SNR). Both the theoretical analysis and computer simulation show that there are three degrading factors due to symbol rate offset. The SNR is inversely proportional to the sum of the estimated coefficients, the half period of the training sequences, and the square of symbol rate offset. If the far-signal-to-channel-noise ratio is 30 dB, then the degradation is significant when the symbol rate offset is more than 10 ^-4. If it is 40 dB, then the degradation is significant when the symbol rate offset is above 3×10^-5     

10 Gbit/s pseudorandom dark soliton data transmission over 1200 km

A 10 Gbit/s pseudorandom (PR) dark soliton data signal has been successfully transmitted over 1200 km for the first time. The dark soliton source was a 1.53 μm DFB LD and was modulated with a push-pull Mach-Zehnder LiNbO₃ intensity modulator. A T-flip-flop circuit was used to generate the PR dark soliton. A one-bit-shifting scheme with a Mach-Zehnder interferometer was used to convert the dark soliton train into a conventional NRZ signal     

Analysis of photoreceptor membrane turnover in a Drosophila visual mutant, rdgA, by electron microscope autoradiography

A Drosophila visual mutant, rdgA, has photoreceptor cells whose rhabdomeres degenerate in several days after eclosion. Incorporations of 3H-amino acids, and 3H-mannose and 3H-glucosamine residues into the photoreceptive membranes were studied in newly emerged rdgA mutant flies by electron microscope autoradiography. The amount of 3H-amino acids incorporated in rdgA rhabdomeres at 3 hr after the injection was about 50%, and that of 3H-sugar residues was about 20% of normal. Together with our previous finding that degradative activity is low in rdgA cell bodies at this time, these data indicate that the supply of photoreceptive membrane proteins is defective in rdgA.     

Robust porous SiOCH/Cu interconnects with ultrathin sidewall protection liners

Robust porous low-k/Cu interconnects have been developed for 65-nm-node ultralarge-scale integrations (ULSIs) with 180-nm/200-nm pitched lines and 100-nm diameter vias in a single damascene architecture. A porous plasma-enhanced chemical vapor deposition (PECVD)-SiOCH film (k=2.6) with subnanometer pores is introduced into the intermetal dielectrics on the interlayer dielectrics of a rigid PECVD-SiOCH film (k=2.9). This porous-on-rigid hybrid SiOCH structure achieves a 35% reduction in interline capacitance per grid in the 65-nm-node interconnect compared to that in a 90-nm-node interconnect with a fully rigid SiOCH. A via resistance of 9.7 /spl Omega/ was obtained in 100-nm diameter vias. Interconnect reliability, such as electromigration, and stress-induced voiding were retained with interface modification technologies. One of the key breakthroughs was a special liner technique to maintain dielectric reliability between the narrow-pitched lines. The porous surface on the trench-etched sidewall was covered with an ultrathin plasma-polymerized benzocyclobuten liner (k=2.7), thus enhancing interline time-dependent dielectric breakdown reliability. The introduction of a porous material and the control of the sidewall are essential for 65-nm-node and beyond scaled-down ULSIs to ensure high levels of reliability.