Methods and systems for realizing a high radiance x-ray source based on a high density electron emitter array are presented herein. The high radiance x-ray source is suitable for high throughput x-ray metrology and inspection in a semiconductor fabrication environment. The high radiance X-ray source includes an array of electron emitters that generate a large electron current focused over a small anode area to generate high radiance X-ray illumination light. In some embodiments, electron current density across the surface of the electron emitter array is at least 0.01 Amperes/mm.sup.2, the electron current is focused onto an anode area with a dimension of maximum extent less than 100 micrometers, and the spacing between emitters is less than 5 micrometers. In another aspect, emitted electrons are accelerated from the array to the anode with a landing energy less than four times the energy of a desired X-ray emission line.

The invention relates to a cathode for an X-ray tube and a corresponding method for assembly. The cathode comprises a filament (22), at least two support structures (21), a body structure comprising a recess for the filament. The filament is provided to emit electrons towards an anode in an electron emitting direction (25). The filament is held by the support structures, which are fixedly connected to the body structure. The filament is totally recrystallized before assembly and has an at least partial helical structure. The support structures comprise a reception end (24) for releasably receiving two ends of the filament by means of a locking mechanism and the complete alignment of the filament and the recess is given by the geometry of the filament, the at least two support structures and the body structure which comprises a recess for the filament. An improved and facilitated cathode assembly with increased reliability of the precision of the positioning in operation is achieved.

The present invention relates to an X-ray tube for X-ray analysis. The X-ray tube comprises an anode having a target surface and a cathode. The cathode comprises an emission loop. The emission loop extends around an axis that passes through the anode, and the cathode and the anode are spaced apart from one another along the axis. Electrons emitted from the cathode irradiate the target surface of the anode to produce X-rays. The X-ray tube further comprises an electron beam guide. The electron beam guide is configured to guide electrons emitted by the cathode, so as to irradiate an area of the anode. The irradiated area is enclosed by a single boundary.

X-ray transparent insulation can be sandwiched between an x-ray window and a ground plate. The x-ray transparent insulation can include aluminum nitride, boron nitride, or polyetherimide. The x-ray transparent insulation can include a curved side. The x-ray transparent insulation can be transparent to x-rays and resistant to x-ray damage, and can have high thermal conductivity. An x-ray window can have high thermal conductivity, high electrical conductivity, high melting point, low cost, and matched coefficient of thermal conductivity with the anode. The x-ray window can be made of tungsten. For consistent x-ray spot size and location, a focusing plate and a filament can be attached to a cathode with an open channel of the focusing plate aligned with a longitudinal dimension of the filament. Tabs of the focusing plate bordering the open channel can be bent to align with a location of the filament.

Provided is a miniaturized X-ray tube including an extractor and provides a miniaturized X-ray tube including a filament that emit electrons if a voltage is applied, a base having two filament through-holes for fixing the filament and for connecting power to both electrodes of the filament, a cylindrical extractor in close contact with the base and surrounding the filament without being in contact with the filament, a cutoff voltage providing unit configured to apply a cutoff voltage between one electrode of the extractor and one electrode of the filament, a body that is formed of a ceramic material, surrounds the extractor, and includes one end in close contact with the base, and a target that is connected to the other end of the body, receives the electrons emitted from the filament, and emits X-rays.

An electron gun includes: a cathode, which has a cathode holder and a cathode body; and a Wehnelt cylinder. The cathode holder receives the cathode body and the Wehnelt cylinder is suitable for bundling free electrons, which can escape from the cathode body toward the Wehnelt cylinder, to form an electron beam. The Wehnelt cylinder is interlockingly arranged, at least in some parts along a first inner surface facing the cathode holder, on an outer surface of the cathode holder and at least partly extends around the cathode holder.

According to one embodiment, an X-ray tube includes an anode including a target surface, and a cathode including a first filament and a focusing electrode. The focusing electrode includes a valley bottom portion, a first inclined plane sloping up from the valley bottom portion in a direction of the anode, a first focusing groove, and a first storage groove. θ1 is greater than 0°. The first focusing groove has a longitudinal axis. One end portion on the first extension line side of the first focusing groove is closer to a first reference surface than the other end portion of the first focusing groove.

Some embodiments include an x-ray source, comprising: an anode; a field emitter configured to generate an electron beam; a first grid configured to control field emission from the field emitter; a second grid disposed between the first grid and the anode; and a middle electrode disposed between the first grid and the anode wherein the second grid is either disposed between the first grid and middle electrode or between the middle electrode and the anode.

Various methods and systems are provided for a cathode of an X-ray imaging system, the cathode comprising a cup and a ceramic insulator having a convex outer surface mating with corresponding pockets on the cup surrounding the ceramic insulator.

An x-ray tube can include an x-ray window sealed to a mount. An inner-collimator can be adjacent to, but not sealed to, the x-ray window. The inner-collimator can be sandwiched between the x-ray window and an insulating-layer. The insulating-layer can span an inner-collimator-aperture of the inner-collimator, forming an isolated cavity at the inner-collimator-aperture. Walls of the cavity can include the x-ray window, the inner-collimator, and the insulating-layer. The x-ray tube can have a light weight, can block x-rays in undesirable directions, and can shape the x-ray beam.