Browsing by Author "Tarntair, FG"

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Chimney-shaped and plateau-shaped gate electrode field emission arrays
(1998)
Tarntair, FG
;
Wang, CC
;
Hong, WK
;
Huang, HK
;
Cheng, HC
A triode structure of chimney-shaped field emitter arrays is proposed in this article. This triode structure includes the chimney-shaped emitter, thermal oxidation dioxide, and the plateau-shaped singlecrystalline silicon gate electrode. For the application of the matrix-addressable and large area flat panel display, the uniform structure of the emitters and the yield become critical manufacturing issues when attempting to control nano-meter size features. The uniformity and yield of the chimney-shaped emitters are very well controlled. The nano-sized gate-to-emitter separations can be created by the changing thickness of the insulator. The uniformity of the insulator and emitter material can be controlled within 3% which can be obtained by most large area thin film deposition tools, not by photolithography.
Chimney-shaped and plateau-shaped gate electrode field emission arrays
(1998)
Tarntair, FG
;
Wang, CC
;
Hong, WK
;
Huang, HK
;
Cheng, HC
A triode structure of chimney-shaped field emitter arrays is proposed in this article. This triode structure includes the chimney-shaped emitter, thermal oxidation dioxide, and the plateau-shaped singlecrystalline silicon gate electrode. For the application of the matrix-addressable and large area flat panel display, the uniform structure of the emitters and the yield become critical manufacturing issues when attempting to control nano-meter size features. The uniformity and yield of the chimney-shaped emitters are very well controlled. The nano-sized gate-to-emitter separations can be created by the changing thickness of the insulator. The uniformity of the insulator and emitter material can be controlled within 3% which can be obtained by most large area thin film deposition tools, not by photolithography.
Chimney-shaped and plateau-shaped gate electrode field emission arrays
(1998-01-01)
Tarntair, FG
;
Wang, CC
;
Hong, WK
;
Huang, HK
;
Cheng, HC
A triode structure of chimney-shaped field emitter arrays is proposed in this article. This triode structure includes the chimney-shaped emitter, thermal oxidation dioxide, and the plateau-shaped singlecrystalline silicon gate electrode. For the application of the matrix-addressable and large area flat panel display, the uniform structure of the emitters and the yield become critical manufacturing issues when attempting to control nano-meter size features. The uniformity and yield of the chimney-shaped emitters are very well controlled. The nano-sized gate-to-emitter separations can be created by the changing thickness of the insulator. The uniformity of the insulator and emitter material can be controlled within 3% which can be obtained by most large area thin film deposition tools, not by photolithography.
Comparative studies on field emission properties of carbon-based materials
(2000-04-01)
Chen, KH
;
Wu, JJ
;
Chen, LC
;
Wen, CY
;
Kichambare, PD
Comparative studies on field emission properties of various carbon-related materials including diamond, amorphous carbon, SiCN films, SiCN nanorods, and carbon nanotubes are presented. While diamond is well known for its potential use in cold cathodes, the emission current of a hydrogen-treated diamond film is relatively small compared to that of amorphous carbon or diamond-like-carbon film. Meanwhile, carbon nanotubes have demonstrated large emission currents at much lower threshold voltages, showing their potential for applications. However, the emission from carbon nanotubes is subjected to significant decay under long-term operation. The emission current and long-term stability can be improved using a new SiCN compound with nanorod morphology. The effective barrier height and the held enhancement factor derived from the Fowler-Nordheim equation are discussed in this paper. (C) 2000 Elsevier Science S.A. All rights reserved.
Enhanced electron emission from phosphorous- and boron-doped diamond-clad Si field emitter arrays
(1996-12-15)
Ku, TK
;
Chen, SH
;
Yang, CD
;
She, NJ
;
Tarntair, FG
A new fabrication technology of polycrystalline diamond-clad Si microtips using microwave plasma chemical vapor deposition (MPCVD) has been developed to improve the characteristics of electron field emission from the pure Si tips. A uniform and smooth coating morphology for the diamond-clad Si tips have been achieved. Electron emission currents of diamond-clad tips are much higher than those of pure Si tips. Such great improvement is attributed to the lowering of the effective work function in the diamond-clad tips. The effects of phosphorus- and boron-doped diamond-clad Si tips have been also studied in comparison with the undoped ones. The current-voltage characteristics of the undoped diamond-clad tips were further enhanced by the in-situ doping of phosphorus or boron due to a higher electron supplement. Moreover, the P-doped diamond-clad tips show a better field emission performance as compared to the B-doped ones. This difference is surmised to be associated with the higher electron conductivity and defect densities of P-doped diamond films.
Enhancement in field emission of silicon microtips by bias-assisted carburization
(2000-11-01)
Kichambare, PD
;
Tarntair, FG
;
Chen, LC
;
Chen, KH
;
Cheng, HC
Ultrathin carbon layers with thicknesses below 50 Angstrom have been deposited on silicon microtip arrays by bias-assisted carburization (BAC) using microwave plasma chemical vapor deposition. The tip radius of these silicon tips is reduced below 55 nm under low deposition temperature. The field emission characterization has been performed in a high-vacuum environment. An enhancement in the field emission is observed of about 3 orders of magnitude in BAC silicon microtips over untreated silicon microtips. With an applied voltage of 1100 V, emission currents of 80 and 120 muA have been achieved for the films grown (at de bias of -200 V for 40 min) with 15% and 25% CH4/H-2 gas ratio, respectively. An emission current of 40 muA has been achieved for the film grown (at de bias of -300 V for 30 min) with 3.5% CH4/H-2 ratio. The BAC silicon emitter has good emission stability at a constant voltage of 1100 V. These investigations indicate that further improvement of this technology will lead to simple and inexpensive field emission display devices. (C) 2000 American Vacuum Society. [S0734-211X(00)10706-1].
Fabrication and characterization of carbon nanotube triodes
(2001-05-01)
Hong, WK
;
Chen, KH
;
Chen, LC
;
Tarntair, FG
;
Chen, KJ
To achieve high emission current density, carbon nanotube triodes have been proposed using recessed oxide as the insulator between the gate and the carbon nanotubes to replace the conventional spacer. An anode current of 10 muA was achieved with a gate voltage of 98 V for a nanotube sample prepared with a growth time of 12 min. Carbon nanotubes synthesized with various growth times were analyzed using a scanning electron microscope and Raman spectroscopy. By increasing the growth time, longer carbon nanotubes were obtained. Effects of the length of the carbon nanotubes on the field emission of the triodes are discussed, Enhanced luminance was obtained as the anode voltage increased from 600V to 1000V. Such carbon nanotube triodes are promising for utilization in future field-emission displays.
Fabrication and characterization of various carbon-clad silicon microtips with ultra-small tip radii
(2000-02-01)
Tarntair, FG
;
Hong, WK
;
Ku, TK
;
She, NJ
;
Chen, CF
Various types of ultra sharp Si microtips and multitips with carbon-clading films were fabricated by microwave plasma chemical vapor deposition (MPCVD). The radii of these Si tips prepared by bias assisted carburization (BAC) can he reduced below 300 Angstrom under a low deposition temperature (<550 degrees C). Field emission characterization was performed in a high vacuum environment. With an applied anode voltage of 1100 V, emission currents of 169 mu A, 198 mu A, and 385 mu A can be achieved from an array of 50 x 50 BAG-clad Si monotips, Si multitips via high bias, and Si multitips via the Ar presputtering technique, respectively. Both the auger electron spectroscopy (AES) and X-ray photo-electron spectroscopy (XPS) studies of the C l s peak suggest that the BAC-cladding is more likely to be a carbon-rich SiC layer or a SiC layer mixed with a small amount of diamond nuclei. This BAC-carbon can be used as an effective nucleation layer for further diamond nuclei. Due to the low field emission, low temperature, and large area growth capability, the sharp BAC-clad Si multitip field emitter arrays are attractive Tor flat panel display applications.
Fabrication and characterization of various carbon-clad silicon microtips with ultra-small tip radii.
(1996)
Ku, TK
;
Chen, SH
;
Yang, CD
;
She, NJ
;
Tarntair, FG
In order to take the advantages of diamond and carbon coating on flat-panel display, unscratched sharp Si microtip arrays have been carburized based on the bias enhanced nucleation (BEN) and low-pressure MPCVD deposition to obtain an ultra-sharp carburized Si FEAs. The tip radii of these BEN-carburized Si tips can be reduced below 300 Angstrom under low deposition temperature (<550 degrees C). Furthermore, some BEN-carburized samples were further deposited by normal diamond growth conditions to form the ultra-sharp DLC-clad Si FEAs with enhanced emission ability.
Field electron emission from C-based emitters and devices
(2001)
Chen, LC
;
Hong, WK
;
Tarntair, FG
;
Chen, KJ
;
Lin, JB
We present the fabrication, characterization and field emission properties of various C-based emitters and devices, which include (1) the diode-type emitters consisting of arrays of carbon-coated Si microtips and carbon nanotubes (CNTs), (2) CNT triodes. and (3) thin-film-transistor (TFT)-controlled CNT field emission devices (FEDs). All the CNTs were deposited by microwave plasma-enhanced chemical vapor deposition. For the first type, each array contains 50 x 50 emitting cells and each individual cell is 3 microns square. Compared to the Si microtips with bias-assisted carburization or diamond cladding, enhancement in field emission by several orders of magnitude of the CNTs arrays was observed. While the diode-type CNT emitters easily achieve the goal of drawing high electron emission current at low macroscopic field, their long-term stability is not satisfactory for practical applications. For the triode-type CNT-FEDs, vertically aligned CNTs with controlled length were directly grown on the Fe-coated Si substrate pre-patterned by photolithography and etching using oxide as the gate insulator, and the emission current from the CNTs was controlled via the gate voltage. For the TFT-controlled CNT-FEDs, CNTs were selectively grown on the drain region of the TFT and the emission current from the CNTs was controlled via the TFT drain current. It should be mentioned that the fabrication procedures are straightforward and can be integrated with current technologies in the well-established semiconductor industry. Both the triode-type CNTs as well as the TFT-controlled CNT-FEDs have demonstrated improved controllability and stability while maintaining high emission current density.
Field emission from quasi-aligned SiCN nanorods
(2000-05-01)
Tarntair, FG
;
Wen, CY
;
Chen, LC
;
Wu, JJ
;
Chen, KH
We report on the preparation and field emission properties of quasi-aligned silicon carbon nitride (SiCN) nanorods. The SiCN nanorods are formed by using a two-stage growth method wherein the first stage involves formation of a buffer layer containing high density of nanocrystals by electron cyclotron resonance plasma enhanced chemical vapor deposition and the second stage involves using microwave plasma enhanced chemical vapor deposition for high growth rate along a preferred orientation. It should be noted that growth of the SiCN nanorods is self-mediated without the addition of any metal catalyst. Scanning electron microscopy shows that the SiCN nanorods are six-side-rod-shaped single crystals of about 1-1.5 mu m in length and about 20-50 nm in diameter. Energy dispersive x-ray spectrometry shows that the nanorod contains about 26 at. % of Si, 50 at. % of C, and 24 at. % of N. Characteristic current-voltage measurements indicate a low turn-on field of 10 V/mu m. Field emission current density in excess of 4.5 mA/cm(2) has been observed at 36.7 V/mu m. Moreover, SiCN nanorods exhibited rather stable emission current under constant applied voltage. (C) 2000 American Institute of Physics. [S0003-6951(00)01117-7].
Field emission properties of two-layer structured SiCN films
(2001-03-15)
Tarntair, FG
;
Wu, JJ
;
Chen, KH
;
Wen, CY
;
Chen, LC
The electron emission characteristics of two-layer structured silicon carbon nitride (SiCN) films, which were composed of amorphous and nanocrystalline phases, were studied. Rutherford backscattering spectroscopy (RBS) was used to determine the composition of the SiCN film. The ratio (Si;C)/N of the SiCN film was kept at approximately 0.75, which is identical to that of Si3N4 him. High resolution X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy were used to investigate the bonding structures of the SiCN films. In comparison with silicon nitride films, the turn-on Voltage (for an emission current of 0.01 mA/cm(2)) of the SiCN films was rower and the emission current densities of the SiCN significantly enhanced. The promising emission properties of the SiCN film could be due to the unique two-layer structure wherein nanocrystalline SiCN was grown on top of the amorphous interlayer with sp(2) CN bond in the SiCN film. (C) 2001 Elsevier Science B.V. All rights reserved.
Field-emission properties of aligned carbon nanotubes
(2000-09-15)
Hong, WK
;
Shih, HC
;
Tsai, SH
;
Shu, CT
;
Tarntair, FG
Dense, well-separated, and aligned carbon nanotubes have been prepared via bias-enhanced microwave plasma chemical vapor deposition. The turn-on fields defined at the emission current density of 10 mu A/cm(2) are about 3.35 V/mu m, 2.54 V/mu m, and 3.54V/mu m, for the immersion times in PdCl2 of 1 min, 20 min, and 40 min,respectively. The corresponding emission current densities are about 0.97 mA/cm(2), 4.5 mA/cm(2), and 0.44 mA/cm(2) at the electric field of 5 V/mu m. The higher emission current obtained from the aligned carbon nanotubes for the immersion time of 20 min is ascribed to the denser and sharper nanotubes formed in this condition.
High current density field emission from arrays of carbon nanotubes and diamond-clad Si tips
(2000-05-01)
Tarntair, FG
;
Chen, LC
;
Wei, SL
;
Hong, WK
;
Chen, KH
Arrays of carbon nanotubes (CNT) and diamond-clad Si tips were grown by microwave plasma-enhanced chemical vapor deposition. The former ones were grown directly on prepatterned cobalt-coated silicon substrate, while the latter ones were grown on Si-tip arrays. Each array contains 50 x 50 emitting cells and each individual cell is 3 mu m square. A maximum effective emission current density of about 17 A/cm(2) (at a macroscopic field of 17.5 V/mu m) has been demonstrated, while a macroscopic emission current density of 10 mA/cm(2) with operating fields around 10 V/mu m can be routinely achieved from an an ay of CNT emitters. In contrast, operating fields above 20 V/mu m were needed to draw a comparable emission current density from all of the diamond-clad Si tips arrays. Emission stability test performed at 40 mA/cm(2) for CNT arrays also showed little sign of degradation. Due to the high efficiency of electron emission, simple sample process, and large area growth capability, field emitter arrays based on CNT are attractive for flat panel display applications. (C) 2000 American Vacuum Society. [S0734-211X(00)08003-3].
Integration of thin film transistor controlled carbon nanotubes for field emission devices
(2001-04-01)
Cheng, HC
;
Hong, WK
;
Tarntair, FG
;
Chen, KJ
;
Lin, JB
A new field emission device composed of carbon nanotubes and a thin film transistor (TFT) has been successfully demonstrated to significantly improve emission stability. Carbon nanotubes are directly integrated in the drain region of the TFT and the emission current from the carbon nanotubes is controlled via the TFT drain current. The fluctuation of the emission current of the TFT-controlled carbon nanotubes can be suppressed to less than 2%, below the fluctuation of uncontrolled carbon nanotubes. The novel field emission device exhibits low-voltage controllability, good emission stability, and structural simplicity, making it promising for application to future field-emission display. (C) 2001 The Electrochemical Society.
Thin-film transistors with polycrystalline silicon films prepared by two-step rapid thermal annealing
(2000-01-15)
Cheng, HC
;
Huang, CY
;
Wang, FS
;
Lin, KH
;
Tarntair, FG
A novel two-step rapid thermal annealing (RTA) process has been developed to significantly reduce the crystallization time for the solid-phase crystallization (SPC) of amorphous silicon films. In comparison with the conventional SPC processes, it not only keeps a low thermal budget but also achieves a larger poly-Si film grain size than that obtained by one-step RTA, and even as large as that obtained by conventional furnace annealing (CFA). Furthermore, poly-Si thin-film transistors fabricated by such a novel annealing scheme possess electrical characteristics superior to those obtained by one-step RTA and comparable to those obtained by long-time CFA.