Fabrication of all-metal field emitter arrays with controlled apex sizes by molding

Abstract

Articles you may be interested inStable, ruggedized, and nanometer-order size transfer mold field emitter array in harsh oxygen radical environment J. Vac. Sci. Technol. B 33, 03C107 (2015); 10.1116/1.4905046 Fabrication of metallic double-gate field emitter arrays and their electron beam collimation characteristics J. Appl. Phys. 112, 093307 (2012); 10.1063/1.4764925 Nanosecond pulsed field emission from single-gate metallic field emitter arrays fabricated by moldinga) J. Vac. Sci. Technol. B 29, 02B117 (2011); 10.1116/1.3569820 Enhancement of ion-induced bending phenomenon using a double-layered film for field emitter array fabrication J. Vac. Sci. Technol. B 28, C2C1 (2010); 10.1116/1.3276096Microelectron field emitter array with focus lenses for multielectron beam lithography based on silicon on insulator waferThe authors proposed a method to fabricate field emitter arrays with uniform apex diameters in tens of nanometer scale based on the molding technique and apply it to fabricate molybdenum field emitter arrays. Apex diameter equal to 23Ϯ 5 nm was observed in a 6 ϫ 6 tip array by high-resolution scanning electron microscope. They also studied the field-emission characteristics in devices with gate electrodes fabricated on top of the arrays by a self-aligned process. In single-gate devices, emission current of up to 20 A per tip with negligible gate leak current was observed. The gate-fabrication process was extended to fabricate double-gated emitters. Further optimization of the fabrication process for higher emission current, together with metallurgical and lithographic methods, is discussed.

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

“…25,26,[33][34][35] The 4 Â 10 4 emitter tips were aligned with 10 lm pitch in a circular area measuring 2.26 mm in diameter. The gate electrodes consisted of 0.5 lm thick molybdenum films.…”

Fabrication of metallic double-gate field emitter arrays and their electron beam collimation characteristics

“…23 To reduce the beam divergence and the transverse electron velocity spread, double-gate FEAs equipped with a beam collimation gate electrode G col in addition to the electron extraction gate electrode G ext have been intensely studied. 5,[7][8][9][24][25][26][27][28][29][30][31] This is due to the fact that the emittance of a FEA can be small only when the individual beamlets are maximally collimated, 1 even though the emittance of individual beamlets is small. 33 In double-gate FEAs, a divergent field emission beam is collimated by applying a negative collimation potential V col to G col .…”

“…This is a difficult task with the normally used polymer etch-back method. 5,8,9 The aims of the present work are to report the fabrication method of our double-gate FEAs in detail, including the FIB assisted G col patterning method and experimentally clarify the impact of the G col aperture diameter on the collimation characteristics. Also, the scalability of the proposed large G col aperture structure is investigated by applying the FIB assisted method to fabricate a 20 Â 20 FEA and test its beam characteristics.…”

“…Research on field emitter arrays (FEAs) has been actively pursued [1][2][3][4][5][6][7][8][9][10][11][12][13] with the aim of realizing high current and high current density cathodes, e.g., for compact microwave vacuum electronic amplifiers, such as traveling wave tubes (TWTs) [14][15][16][17] and compact free electron lasers. 7,18 FEAs are expected to help simplify the gun design and extend the operation range of such TWTs.…”

Highly collimated electron beams from double-gate field emitter arrays with large collimation gate apertures

“…20 The molybdenum emitters with tip apex diameters of 10-20 nm have a square base with a side length of ϳ1.5 m and a height of ϳ1.2 m. The emitter arrays are supported by ϳ400 m of electroplated nickel. The G ext apertures were fabricated by a self-aligned etch-back and wet-etching process, 20 which leads to square apertures with rounded corners.…”