摘要:
A method of forming a gate valve for use in a high vacuum environment of an electron gun by machining a core of non-magnetic nickel-chromium-molybdenum-iron-tungsten-silicon-carbon alloy that is weldable with nickel alloys and has a tensile strength of about 750 megapascals, machining a cladding of nickel-iron, welding the core to the cladding to form the gate valve, and machining the gate valve so as to remove any dimensional differences at an interface between the core and the cladding. In this manner, because the final mechanical tolerance is controlled by machining instead of part assembling, extremely high alignment accuracy is obtained. The final part provides field shielding as provided by the nickel alloy shell, low stray field provided by the non-magnetic alloy, good vacuum performance, and tight mechanical tolerance control. Also, because the alloy has the advantage of a low oxidation rate in comparison to stainless steel and titanium, there is less contamination buildup due to conditions such as electron beam bombardment.
摘要:
A method of forming a gate valve for use in a high vacuum environment of an electron gun by machining a core of non-magnetic nickel-chromium-molybdenum-iron-tungsten-silicon-carbon alloy that is weldable with nickel alloys and has a tensile strength of about 750 megapascals, machining a cladding of nickel-iron, welding the core to the cladding to form the gate valve, and machining the gate valve so as to remove any dimensional differences at an interface between the core and the cladding. In this manner, because the final mechanical tolerance is controlled by machining instead of part assembling, extremely high alignment accuracy is obtained. The final part provides field shielding as provided by the nickel alloy shell, low stray field provided by the non-magnetic alloy, good vacuum performance, and tight mechanical tolerance control. Also, because the alloy has the advantage of a low oxidation rate in comparison to stainless steel and titanium, there is less contamination buildup due to conditions such as electron beam bombardment.
摘要:
A component for use in a high vacuum environment, the component including a core of non-magnetic Hastelloy with a cladding of nickel-iron covering the core at least in part. The component can be, for example, at least one of a gate valve for use in a high vacuum environment of an electron gun, a bearing, a slide way, a gate valve bearing, a rotary slide, a linear slide, an electron beam column, and electron beam chamber, and a vacuum chamber. In this manner, because the final mechanical tolerance is controlled by machining instead of part assembling, extremely high alignment accuracy is obtained. The final part provides field shielding as provided by the nickel alloy shell, low stray field provided by the non-magnetic Hastelloy, good vacuum performance, and tight mechanical tolerance control. Also, because Hastelloy has the advantage of a low oxidation rate in comparison to stainless steel and titanium, there is less contamination buildup due to conditions such as electron beam bombardment.
摘要:
One embodiment relates to an apparatus for inspecting a substrate using charged particles. The apparatus includes an illumination subsystem, an objective subsystem, a projection subsystem, and a beam separator interconnecting those subsystems. The apparatus further includes a detection system which includes a scintillating screen, a detector array, and an optical coupling apparatus positioned therebetween. The optical coupling apparatus includes both refractive and reflective elements. Other embodiments and features are also disclosed.
摘要:
In one embodiment, a first vacuum chamber of an electron beam column has an opening which is positioned along an optical axis so as to pass a primary electron beam that travels down the column. A source that emits electrons is positioned within the first vacuum chamber. A beam-limiting aperture is configured to pass a limited angular range of the emitted electrons. A magnetic immersion lens is positioned outside of the first vacuum chamber and is configured to immerse the electron source in a magnetic field so as to focus the emitted electrons into the primary electron beam. An objective lens is configured to focus the primary electron beam onto a beam spot on a substrate surface so as to produce scattered electrons from the beam spot. Controllable deflectors are configured to scan the beam spot over an area of the substrate surface. Other features and embodiments are also disclosed.
摘要:
An electron gun of the type having an electron emitter for emitting electrons, including an electrostatic lens and a magnetic lens formed by pole pieces with a winding coil disposed between the magnetic pole pieces. The magnetic lens forms a rotationally symmetrical magnetic field in a gap formed by the pole pieces. The magnetic field forms the magnetic lens and focuses the electrons emitted from the emitter. A vacuum tube separates the electron gun from the magnetic lens. The electron gun is sealed in a vacuum by the vacuum tube and the magnetic lens is shielded in air.
摘要:
One embodiment relates to an electron-beam apparatus for defect inspection and/or review of substrates or for measuring critical dimensions of features on substrates. The apparatus includes an electron gun and an electron column. The electron gun includes an electron source configured to generate electrons for an electron beam and an adjustable beam-limiting aperture which is configured to select and use one aperture size from a range of aperture sizes. Another embodiment relates to providing an electron beam in an apparatus. Advantageously, the disclosed apparatus and methods reduce spot blur while maintaining a high beam current so as to obtain both high sensitivity and high throughput.
摘要:
One embodiment relates to an apparatus for generating two spatially overlapping electron beams on a specimen. A first electron beam source is configured to generate a low-energy electron beam, and an energy-dispersive device bends the low-energy electron beam towards an semitransparent electron mirror. The semitransparent electron mirror is biased to reflect the low-energy electron beam. A second electron beam source is configured to generate a high-energy electron beam that passes through an opening in the semitransparent electron mirror. Both the low- and high-energy electron beams enter the same energy-dispersive device that bends both beams towards the specimen. A deflection system positioned between the high-energy electron source and semitransparent electron mirror is configured to deflect the high-energy electron beam by an angle that compensates for the difference in bending angles between the low- and high-energy electron beams introduced by the energy-dispersive device. Other embodiments are also disclosed.
摘要:
One embodiment pertains to an apparatus for reflection electron beam lithography, including at least illumination electron-optics, an electron-reflective pattern generator, projection electron-optics, a moving stage holding a target substrate, control circuitry, and a deflection system. The illumination electron-optics is configured to form an illumination electron beam. The electron-reflective pattern generator configured to generate an electron-reflective pattern of pixels and to reflect the illumination electron beam using the pattern to form a patterned electron beam. The projection electron-optics is configured to project the patterned electron beam onto the moving target substrate. The control circuitry is configured to shift the generated pattern in discrete steps in synchronization with the stage motion. The deflection system is configured to deflect said projected patterned electron beam so as to compensate for said stage motion in between discrete shifts of said generated pattern. Other features and embodiments are also disclosed.
摘要:
One embodiment relates to an apparatus for generating a dual-energy electron beam. A first electron beam source is configured to generate a lower-energy electron beam, and a second electron beam source is configured to generate a higher-energy electron beam. A holey mirror is biased to reflect the lower-energy electron beam. The holey mirror also includes an opening therein through which passes the higher-energy electron beam, thereby forming the dual-energy electron beam. A prism array combiner introduces a first dispersion between the lower-energy electron beam and the higher-energy electron beam within the dual-energy electron beam. A prism array separator is configured to separate the dual-energy electron beam traveling to a substrate from a scattered electron beam traveling away from the substrate. The prism array separator introduces a second dispersion which compensates for the dispersion of the prism array combiner. Other embodiments are also disclosed.