In an electron tube, the meta-surface emits an electron in response to an incidence of the electromagnetic wave. The first and second electrodes are spaced away from each other, and apply potentials different from each other to the meta-surface. A holder is disposed in the housing and holds the electron emitter. A first conductive line of the meta-surface is electrically connected to the first electrode. A second conductive line of the meta-surface is spaced away from the first conductive line, and is electrically connected to the second electrode. The first conductive line extends from the first electrode to the second conductive line. The second conductive line extends from the second electrode to the first conductive line.

A technique relates to a semiconductor device. An emitter electrode and a collector electrode are formed in a dielectric layer such that a nanogap separates the emitter electrode and the collector electrode, a portion of the emitter electrode including layers. A channel is formed in the dielectric layer so as to traverse the nanogap. A top layer is formed over the channel so as to cover the channel and the nanogap without filling in the channel and the nanogap, thereby forming a vacuum channel transistor structure.

The purpose of the present invention is to provide a charged particle source that exhibits small energy dispersion for charged particle beams emitted under a high angular current density condition and allows stable acquisition of large charged particle currents even for a small light source diameter. The charged particle source according to the present invention has a spherical virtual cathode surface from which charged particles are emitted, and the virtual cathode surface for charged particles emitted from a first position on a tip end surface of an emitter and the virtual cathode surface for charged particles emitted from a second position on the tip end surface of the emitter match each other (see FIG. 4).

The present invention is directed to a method for the fabrication of electron field emitter devices, including carbon nanotube (CNT) field emission devices. The method of the present invention involves depositing one or more electrically conductive thin-film layers onto a electrically conductive substrate and performing lithography and etching on these thin film layers to pattern them into the desired shapes. The top-most layer may be of a material type that acts as a catalyst for the growth of single- or multiple-walled carbon nanotubes (CNTs). Subsequently, the substrate is etched to form a high-aspect ratio post or pillar structure onto which the previously patterned thin film layers are positioned. Carbon nanotubes may be grown on the catalyst material layer. The present invention also described methods by which the individual field emission devices may be singulated into individual die from a substrate.

The present invention is directed to a method for the fabrication of electron field emitter devices, including carbon nanotube (CNT) field emission devices. The method of the present invention involves depositing one or more electrically conductive thin-film layers onto a electrically conductive substrate and performing lithography and etching on these thin film layers to pattern them into the desired shapes. The top-most layer may be of a material type that acts as a catalyst for the growth of single- or multiple-walled carbon nanotubes (CNTs). Subsequently, the substrate is etched to form a high-aspect ratio post or pillar structure onto which the previously patterned thin film layers are positioned. Carbon nanotubes may be grown on the catalyst material layer. The present invention also described methods by which the individual field emission devices may be singulated into individual die from a substrate.

Electron emitters and methods of fabricating the electron emitters are disclosed. According to certain embodiments, an electron emitter includes a tip with a planar region having a diameter in a range of approximately (0.05-10) micrometers. The electron emitter tip is configured to release field emission electrons. The electron emitter further includes a work-function-lowering material coated on the tip.

Electron emitters and methods of fabricating the electron emitters are disclosed. According to certain embodiments, an electron emitter includes a tip with a planar region having a diameter in a range of approximately (0.05-10) micrometers. The electron emitter tip is configured to release field emission electrons. The electron emitter further includes a work-function-lowering material coated on the tip.

In a vacuum chamber (1), an emitter (3) and a target (7) are opposed to each other. A guard electrode (5) is disposed around an outer circumference of an electron generating portion (31) of the emitter (3). A supporting part (4) supports the emitter (3) movably in an end-to-end direction of the vacuum chamber (1). Reforming treatment is performed on the guard electrode (5) by operating the supporting part (4), moving the emitter (3) to an open end (21) side (non-discharge position) and applying a voltage to repeatedly effect discharge on the guard electrode (5) in a state where field emission from the electron generation portion (31) is suppressed. After the reforming treatment, the supporting part (4) is again operated. The emitter (3) is moved to an open end (22) side (discharge position) and placed in a state where field emission from the electron generation portion (31) is allowed.

In a vacuum chamber (1), an emitter (3) and a target (7) are opposed to each other. A guard electrode (5) is disposed around an outer circumference of an electron generating portion (31) of the emitter (3). A supporting part (4) supports the emitter (3) movably in an end-to-end direction of the vacuum chamber (1). Reforming treatment is performed on the guard electrode (5) by operating the supporting part (4), moving the emitter (3) to an open end (21) side (non-discharge position) and applying a voltage to repeatedly effect discharge on the guard electrode (5) in a state where field emission from the electron generation portion (31) is suppressed. After the reforming treatment, the supporting part (4) is again operated. The emitter (3) is moved to an open end (22) side (discharge position) and placed in a state where field emission from the electron generation portion (31) is allowed.

opening edge surface (45a) of an emitter supporting unit female screw bore (45) provided at an emitter supporting unit (4) extends along radial direction of the emitter supporting unit female screw bore (45). An emitter supporting unit operation hole (32) provided at a flange portion (30a) of a vacuum enclosure (11) has shape into which one selected from a position adjustment shaft (6) and a pressing shaft (9) can be inserted from their shaft tip sides. The position adjustment shaft is provided, on an outer circumferential surface of its tip (61), with a tip side male screw portion (61a) that can be screwed into the emitter supporting unit female screw bore (45). The pressing shaft has, at its tip (91), a tip surface (91a) having a larger diameter than an opening diameter of the emitter supporting unit female screw bore (45) and extending along radial direction of the pressing shaft.