Microscopic field emission investigation of nanodiamond and AlN coated Si tips

Abstract

High current density field emission from arrays of carbon nanotubes and diamond-clad Si tips Demonstration of Li-based alloy coatings as low-voltage stable electron-emission surfaces for field-emission devices J. Appl. Phys. 85, 8405 (1999); 10.1063/1.370688 Model calculations of internal field emission and J-V characteristics of a composite n -Si and N-diamond cold cathode sourceWe have investigated the suitability of nanodiamond ͑ND͒ and AlN coated Si tip arrays for cold cathodes by means of a field emission scanning microscope combined with scanning electron microscopy. The ND coated tips required an average extraction voltage U(10 nA) of 360 V for 10 m electrode distance and yielded stable emission up to currents of 10-50 A. The rather nonuniform emission distribution of the arrays (80 VϽU(10 nA)Ͻ1800 V) was correlated with the varying morphology of the ND tips. Field-enhancing nanoprotrusions were observed at the apex of the strongest emitters. The AlN coated tips showed strong activation effects at emission currents below 10 nA or after annealing at 250°C resulting in an average U(10 nA) of 410 V, improved lateral emission uniformity (150 VϽU(10 nA)Ͻ600 V), and stable currents up to 1-10 A. Direct high current processing of such emitters led to a partial destruction of the apex. Different field emission mechanism will be discussed for ND and AlN coatings.

Reliability tests of gated silicon field emitters for use in space

“…Whilst the model of a gradual deterioration in the tip population is supported by slow changes in current and voltage measurements, there is little observational evidence of degraded tip populations. Photographs claiming to show partially eroded single tips are promising (Gunther et al 2001, Karain et al 1994, but not necessarily indicative of bulk array behaviour. There appears to be more evidence for the 'shallow ion implantation' mechanism proposed by Reuss and Chalamala (2003) which is supported by detailed studies at controlled pressures of large arrays, with >4 million molybdenum tips.…”

Field emission properties of Si tip arrays coated with N-doped SrTiO3 thin films at different substrate temperature

“…6 In order to improve the FE performance of silicon emitters, the surface of silicon tips was functionalized by some carbon-based coatings such as diamondlike carbon and CN x thin films. [7][8][9][10] However, the intrinsic high compressive stress and low thermal stability restrict their practical applications. As an alternative candidate, the silicon tip arrays modified by ferroelectric thin films 11,12 were developed recently to enhance their FE behavior.…”