Abstract: One embodiment disclosed relates to a method for fabricating a calibration sample. The method includes lithographically patterning a first side of a wafer with a pattern of a self-supporting membrane, etching the first side of the wafer to form the self-supporting membrane in a layer on the first side, and etching a second side of the wafer to reach the layer so as to suspend the membrane over an empty space. Another embodiment disclosed relates to a charged particle beam system. The system includes a charged particle source, a focusing column and lens assembly, a detector, and a suspended membrane calibration sample. Another embodiment disclosed relates a suspended membrane calibration sample for a charged particle beam system. The calibration sample includes a plurality of calibration patterns in an array, a suspended membrane that is self-supporting and includes the plurality of calibration patterns, and an empty space underneath the membrane.

Abstract: One embodiment relates to an apparatus for high-resolution electron beam imaging. The apparatus includes an energy filter configured to limit an energy spread of the electrons in the incident electron beam. The energy filter may be formed using a stigmatic Wien filter and a filter aperture. Another embodiment relates to a method of forming an incident electron beam for a high-resolution electron beam apparatus. Another embodiment relates to a stigmatic Wien filter that includes curved conductive electrodes. Another embodiment relates to a stigmatic Wien filter that includes a pair of magnetic yokes and a multipole deflector. Other embodiments, aspects and features are also disclosed.

Abstract: 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.

Abstract: One embodiment disclosed relates to a multiple-beamlet electron beam imaging apparatus for imaging a surface of a target substrate. A beam splitter lens array is configured to split the illumination beam to form a primary beamlet array, and a scanning system is configured to scan the primary beamlet array over an area of the surface of the target substrate. In addition, a detection system configured to detect individual secondary electron beamlets. Another embodiment disclosed relates to a method of imaging a surface of a target substrate using a multiple-beamlet electron beam column. Other features and embodiments are also disclosed.

Abstract: 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.

Abstract: One embodiment disclosed relates to a multiple-beamlet electron beam imaging apparatus for imaging a surface of a target substrate. A beam splitter lens array is configured to split the illumination beam to form a primary beamlet array, and a scanning system is configured to scan the primary beamlet array over an area of the surface of the target substrate. In addition, a detection system configured to detect individual secondary electron beamlets. Another embodiment disclosed relates to a method of imaging a surface of a target substrate using a multiple-beamlet electron beam column. Other features and embodiments are also disclosed.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: One embodiment disclosed relates to an electron beam apparatus for inspection of a semiconductor wafer, wherein substantially an entire area of the wafer surface is scanned without moving the stage. A cathode ray tube (CRT) gun may be used to rapidly (and cost effectively) scan the beam over the wafer. Another embodiment disclosed relates to a high-speed automated e-beam inspector configured to scan the e-beam in one dimension while translating the wafer in a perpendicular direction. The translation may be linear, or alternatively, may be in a spiral path. Other embodiments are also disclosed.

Abstract: A method for inspecting samples uses a multiple beam electron system having a uniform magnetic focusing field. Deflection of the incident electron beams is produced by deflector plates generating an electrostatic deflection force which produces a uniform force on the electron beams. Thermal field emission sources generate incident electron beams towards at least two portions of the sample. A detector array collects multiple detection electrons.