Browsing by Author "Das, D"

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Generally applicable self-masked dry etching technique for nanotip array fabrication
(2004-03-01)
Hsu, CH
;
Lo, HC
;
Chen, CF
;
Wu, CT
;
Hwang, JS
Well-aligned nanotip arrays were fabricated by electron cyclotron resonance (ECR) plasma process using gas mixtures of silane, methane, argon, and hydrogen. The resultant tips have nanoscale apexes (similar to1 nm) with high aspect ratios (similar to50), which were achieved by simultaneous SiC nanomask formation and dry etching during ECR plasma process. This technique was applied to a variety of substrates such as silicon, polycrystalline silicon, gallium nitride, gallium phosphide, sapphire, and aluminum, indicating its general applicability. High-resolutiontransmission electron microscopy and Auger depth profile analyses revealed that the SiC cap, with Si:C ratio of 1:1, exhibited 3C-SiC and 2H-SiC structure on Si and GaP, respectively, with heteroepitaxial relationship. This one-step self-masked dry etching technique enables the fabrication of uniform nanotip arrays on various substrates over large area at low process temperatures, thereby demonstrating a high potential for practical industrial application.
SiC-capped nanotip arrays for field emission with ultralow turn-on field
(2003-08-18)
Lo, HC
;
Das, D
;
Hwang, JS
;
Chen, KH
;
Hsu, CH
Silicon nanotips with tip diameter and height measuring 1 nm and 1 mum, respectively, and density in the range of 10(9)-3x10(11) cm(-2), were fabricated monolithically from silicon wafers by electron cyclotron resonance plasma etching technique at a temperature of 200 degreesC. Field emission current densities of 3.0 mA/cm(2) at an applied field of similar to1.0 V/mum was obtained from these silicon nanotips. High-resolution transmission electron microscope and Auger electron spectroscopy analyses concluded that the nanotips are composed of monolithic silicon and nanometer-size SiC cap at the top. A 0.35 V/mum turn-on field to draw a 10 muA/cm(2) current density was demonstrated, which is much lower than other reported materials. The excellent field emission property demonstrated by these nanotips, which were fabricated by a process integrable to the existing silicon device technology at low temperatures, is a step forward in achieving low-power field emission displays and vacuum electronic devices. (C) 2003 American Institute of Physics.