The enhanced field emission from microtips covered by ultrathin layers

Abstract

The influence of different types of covering on electron field emission from silicon tips has been studied. For this a series of silicon tip array structures, namely (i) structures with porous silicon layers on the tops of the tips, (ii) tips covered with carbon films, (iii) silicon tips implanted by hydrogen, and (iv) cesium-enriched silicon tips, has been prepared and investigated. The comparison and characterization of various structures using effective work functions, field enhancement factors, and effective emission areas obtained from Fowler - Nordheim plots have been performed. Models and mechanisms of enhancement of the electron field emission have been proposed.

Analysis of the band structure of tetrahedral diamondlike crystals with valence bonds: Prediction of materials with superhigh hardness and negative electron affinity

“…[11][12][13] The relation between effective E gap and X is also fulfilled to within 0.5 eV: E gap ϩXϭ5 eV was obtained by Robertson, 11 E gap ϩX T ϭ4.5Ϫ5.5 eV also was obtained in our works. 12,13 So, for these cases it is possible to estimate the indicated quantities from relation ͑1͒ and, in addition, some technology parameters like hydrogen content, refraction index n, etc., can be estimated. [22][23][24] Calculations of the effective lattice constants from the data of valence radii of atoms r as Lϭrϫ4/ͱ3 have been performed for the following compositions: CH 4 , SiH 4 , and GeH 4 .…”

“…[8][9][10][11][12][13][14][15] Hence, the energy gap will decrease in accordance with a simple relation…”

“…The reason for that is that the optical spectroscopy measurements clearly demonstrate the existence of the forbidden gap, i.e., noticeable values of E gap , which can vary from about tenths of eV to more then 4 eV. [11][12][13] The relation between effective E gap and X is also fulfilled to within 0.5 eV: E gap ϩXϭ5 eV was obtained by Robertson, 11 E gap ϩX T ϭ4.5Ϫ5.5 eV also was obtained in our works. 12,13 So, for these cases it is possible to estimate the indicated quantities from relation ͑1͒ and, in addition, some technology parameters like hydrogen content, refraction index n, etc., can be estimated.…”

Field Emission from Carbon Films Deposited by Controlled-Low-Energy Beams and CVD Sources

“…A correlation also has been observed between increasing film roughness (at low depositionẽ nergy) and a lower & for FE [15]. In addition, several groups have demonstrated that J ultrathin a-D coatings (ranging from -2 nm to -30 nm) can enhance FE fi-om Spindt tip c F arrays [16][17][18][19]. This may be a hot-electron effect with the electrons injected from a -c metallic substrate layer and tunneling through the a-D coating [18].…”

Silicon doped diamond-like carbon films as a coating for improvement of electron field emission

“…[1][2][3][4][5][6][7][8] The low electron affinity, chemical endurance, and high thermal conductivity of DLC films allow one to greatly enhance the emission parameters of Si emitters. To improve the emission properties of silicon tip emitters coating with diamond-like carbon ͑DLC͒ films is widely used.…”