Fabrication and characterization of HfC coated Si field emitter arrays

Abstract

Fabrication and electrical characterization of high aspect ratio silicon field emitter arrays Fabrication and characterization of silicon field emitter arrays with focusing electrode by the chemical mechanical polishing processWe fabricated hafnium carbide ͑HfC͒ coated Si field emitter arrays ͑HfC FEAs͒ with an extraction-gate electrode to improve the emission characteristics of Si FEAs. Hafnium carbide thin film was deposited by inductively coupled plasma-assisted magnetron sputtering. The HfC film was characterized by x-ray photoelectron spectroscopy and x-ray diffraction measurement, and was found to be ͑111͒-oriented polycrystalline film. The HfC FEAs exhibited superior performance. An emission of more than 10 mA could be obtained from the 16 000 tip array, which is 20 times higher than that for Si FEAs. The operational voltage for emission of 1 A decreased from 61 to 45 V due to the HfC coating. The long-term emission characteristics were also measured. Si FEAs degraded rapidly even in an ultrahigh vacuum chamber. However, the emission degradation in the HfC FEAs was much slower. The number of active tips was counted using an electrostatic-lens projector, and the results revealed that the HfC FEAs had six times as many tips as the Si FEAs had.

A new method for nanometer scale imaging of field emission current distribution

“…The comparison of the LBH and FE images indicates that the FE current is larger from the sites where the local work function is lower. FE from polycrystalline HfC films Covering of Si field emission arrays (FEA) with the HfC thin films has been proved to be quite effective to improve the electron emission characteristics [6]. In this study, the HfC thin films are deposited in a separate system on the Si(100) substrates in the same condition as in the case of the HfC covered FEA's.…”

Nanometer-scale Distributions of Field Emission Current Measured with Scanning Tunneling Microscopy

“…The HfC thin film has been proved to be effective as a coating material to improve the FE properties of Si field emission arrays [11]. In this study, polycrystalline HfC films are deposited on a Si(1 11) substrate in a separate magnetron sputtering system in the same condition as in the case of the formation of the HfC layer for covering Si FEA tip apex.…”

A low-vacuum ionization gauge with HfC-modified carbon nanotube field emitters

“…It has been widely used in Spindt field-emission arrays to improve the stability of the emission current. 10,11 Zhang et al obtained a stable emission of CNTs in poor vacuum by depositing a Hf film onto the CNTs and then annealing them at 1200°C to form HfC, suggesting a promising way of improving the CNT's lifetime at low vacuum. 12 In this paper, we present a low-vacuum ionization gauge with screenprinted CNTs.…”