Emission statistics for Si and HfC emitter arrays after residual gas exposure

Abstract

Articles you may be interested inField emitter array with a memory function for ultrahigh luminance field emission display Field emission arrays ͑FEAs͒ comprising 100 Si or HfC coated Si emitters have been fabricated. The FEAs emission properties were measured in ultra high vacuum conditions and after being subject to Ar and O 2 residual gases with partial pressures in the range 10 −6 to 10 −4 Pa. The influence of residual gases on the FEAs field emission properties has been comparatively assessed using the model parameter extraction method. The array field emission model uses equations that describe the electron emission current from individual emitters of given radius R and work function together with nonuniform distribution functions giving the dispersion of these parameters within the array. A simplified relationship for the array emission current depending on a single integral instead of a double one has been derived. A nonlinear extraction algorithm using partial derivatives of the objective function is used, which gives fast and accurate results. Both Si and HfC emitters exhibit ͑to a different degree͒ tightening of the radius distribution with time and more uniform emission, when exposed to O 2 residual gas. The current degradation of Si and HfC arrays, when exposed to Ar residual gas, is mostly associated with the work function increase. HfC emitters have higher emission currents, lower noise level, and better stability of the emission than Si emitters. These properties are discussed in terms of the array parameter statistics.

Parameter dispersion characterization for arrays of HfC-coated emitters on poly-Si substrate

“…[7][8][9][10][11] Therefore, only the general modeling framework will be outlined in this section, and some included features will be discussed. [7][8][9][10][11] Therefore, only the general modeling framework will be outlined in this section, and some included features will be discussed.…”

“…8,9 The distribution function for R FIG. The nonuniform distribution functions f 1 ͑R , R 0 , R ͒ ͑log normal͒ and f 2 ͑ , min , ͒ ͑single peak͒, giving the dispersion of the radius and work function within the array, have been used.…”

“…9 The Ī tip ͑V g ͒ part of the integrand represents a median current for emitters with different work functions: 9 The Ī tip ͑V g ͒ part of the integrand represents a median current for emitters with different work functions:…”

Electron beam collimation with a 40 000 tip metallic double-gate field emitter array and in-situ control of nanotip sharpness distribution

“…Another promising method is the bombardment of ions generated by glow-discharge 28 or by electron impact ionization using the field emission current. [29][30][31][32] In particular, an improvement of the beam uniformity by in-situ noble gas conditioning for single-gate molybdenum FEAs was demonstrated recently. 32 However, no study has been reported for the beam uniformity control of double-gate FEAs.…”

Emission and focusing characteristics of volcano-structured double-gated field emitter arrays

“…The HfC coating lowers the operation voltage of the emitter and extends the operation lifetime. 7,8 The height of the extraction electrode was adjusted as the same as the height of the tip. The diameter of the extraction gate hole was about 0.5 m. A, B, and C represent the VDG-FEAs with hf = + 220 nm, 0 nm, and −470 nm, respectively.…”