Yih-Ming Liu

A method to fabricate field emitters using electroless codeposited composite of MWNTs and nickel

A method to fabricate good carbon nanotube (CNT) field emitters using electroless codeposition and CNT purification techniques was developed. Multiwalled CNTs (MWNTs) were codeposited with Ni to form a composite layer acting as the emitter. This composite layer is uniform in thickness and the MWNTs distributed in Ni matrix show a strong adhesion to the substrate. To ensure the emitting quality and good dispersion of MWNTs in the composite, heat annealing and acid immersion process were employed. The composite film shows good emission uniformity and the current density of 1.0 mA/cm 2 was obtained at about 5.7 V/μm.

Improvement of lighting uniformity and phosphor life in field emission lamps using carbon nanocoils

The lighting performances and phosphor degradation in field emission lamps (FELs) with two different kinds of cathode materials-- multiwalled carbon nanotubes (MWCNTs) and carbon nanocoils (CNCs)--were compared. The MWCNTs and CNCs were selectively synthesized on 304 stainless steel wire substrates dip-coated with nanosized Pd catalysts by controlling the growth temperature in thermal chemical vapor deposition, and the film uniformity can be optimized by adjusting the growth time. FELs were successfully fabricated by assembling these cathode filaments with a glass bulb-type anode. The FEL with the CNC cathode showed much higher lighting uniformity and light-spot density and a lower current at the same voltage than that with the MWCNT cathode filament, and its best luminous efficiency was as high as 75 lm/W at 8 kV. We also found that, for P22, the phosphor degradation can be effectively suppressed by replacing MWCNTs with CNCs in the cathode, due to the much larger total bright spot area and hence much lower current density loading on the anode.

The inkjet printing of catalyst Pd ink for selective metallization apply to product antenna on PC/ABS substrate

In this paper, a simple and effective method to fabricate conductive antenna metal pattern on plastic substrates PC/ABS (poly(carbonate/Acrylonitrile-Butadiene-Styrene)) is described. This methods involves inkjet printing of copolymer/noble metal nanopartical-based ink on a PC/ABS substrate to create the catalyst site, onto which is subsequently deposited by an electroless plating method, to obtain metal pattern. The main challenge in electroless plating on plastics is to establish a good adhesion between the substrate and metallic film. The PC/ABS substrate was etching by environmental friendly etching solution, after printing, the plastic were immersed in an electroless plating bath to deposition Ni-P pattern. The prepared nickel film thickness is 11μm, which is excellent adhesion of the deposited Ni-P coating to the substrate according to ASTM D3359-78. Finally, a WWAN antenna was formed then test the Radiation characteristics.

Defect-Free Copper Filling Using Nonisothermal Electroless Deposition with Fluorocarbon Surfactant

Electroless copper bottom-up filling of patterned substrates using nonisothermal deposition (NITD) with the addition of adequate surfactant was demonstrated. Combining the inhibitive ability of adequate surfactant with the higher driving force of NITD method, superfill of vias or trenches using only one inhibitor in the copper damascene of integrated circuits (ICs) was achieved. We tested several commercial surfactant agents and found that fluorinated alkyl quaternary ammonium iodides (FC) is best compatible to our NITD method. Void-free copper-filled features can be obtained by introducing the surfactant FC into the electroless bath of NITD. Furthermore, using our method, the conductivity of copper film was not negatively affected. We conclude that the surfactant FC combined with NITD method is very promising for the applications in filling trenches and vias with copper films in the IC industry.

Helical-Cathode Bulb-Shaped Field Emission Lamps Using Carbon Nanocoil Electron Emitters

Bulb-shaped field emission lamps (FELs) with a helical cathode filament were simulated and fabricated in this research. The light bulbs comprised a helical stainless steel filament cathode grown with carbon nano-coils (CNCs) and an Al anode deposited on the bottom hemisphere of a 60-mm-diameter glass bulb. White light was generated when the field-emitted electrons bombarded a layer of three-color phosphor coated on the anode. A numerical simulation model for the helical-cathode FELs was constructed, and the field emission (FE) performance was carefully studied. Due to the screening effect, the electric field strength as well as the FE current density on the inner side of the helix dramatically decreased with decreasing helical pitch. Real FELs using cathodes with various helical radii and pitches were fabricated and their FE currents were measured. The theoretical and experimental results were in good agreement. A maximum total FE current was found at a pitch of 16 mm (helical radius = 2 mm), where the optimum trade-off between a large total surface area and a small screening effect was obtained. The optimized FEL showed a total luminous flux of about 220 lm at an applied voltage of 8 kV and a color rendering index of 94. Compared to a straight filament cathode, a helical cathode offered a higher total FE current or, alternatively, a lower current density and a longer cathode life, if we fix the total current by using a lower voltage.

The effect of a nickle layer for the field emission properties of carbon nano-fiber

In this paper, we show that the field emission current of carbon nano-fibers (CNFs) is significant improved by introduction of a thin nickel layer on the cathode. Carbon nano-fibers were synthesized by chemical vapor deposition using Pd as catalyst on a 304 stainless steel filament that electroplated with a thin nickel layer. The field emission current increased from 0.424 mA to 4.12 mA with respect to the cathode without a nickel layer at 8000 V. After the aging process, we found that at different aging voltage, the morphology of CNCs was also changed.

Modelling and simulation of power controllable field-emission lamps using carbon nano coil cathodes

In this paper, we demonstrate an easy way to fabricate the power controllable field emission lamps by computing simulation. Based on our previous research, we use SolidWorks® to build a three dimension model and using Comsol Multiphysics 4.1a to calculate the electric field distribution on a straight 304 stainless steel filament with 1mm radius cathode and on it we cut a notch with various lengths. Simulation results show that the electric field on the notch is increased with notch length. By adjust the notch length on the cathode; we can control the power of the field emission lamps.

The in-situ Annealing of Electroless Deposited Copper Films Using NITD Method for ULSI

In this paper we demonstrate the feasibility of direct electroless plating of copper in the NITD system with in-situ annealing treatment. As a result of the high temperature effect during deposition, the peak ratio of Cu (111 )/Cu (200) of copper film reached 19. The resistivity of as-deposited Cu layer was as low as 2.45 muOmega-cm. The NTID system, using single step to deposit metal film, has several advantages that can discard the post-annealing and simplify the deposition processes. It has potential for the application on ULSI.