Abstract: An objective lens for forming an image of an object. The objective lens includes, sequentially from an image side to an object side, a first lens group having negative refractive power, and a second lens group having positive refractive power.

Abstract: An optical system used in a charged particle beam inspection system. The optical system includes one or more optical lenses, and a compensation lens configured to compensate a drift of a focal length of a combination of the one or more optical lenses from a first medium to a second medium.

Abstract: An optical height detection system in a charged particle beam inspection system. The optical height detection system includes a projection unit including a modulated illumination source, a projection grating mask including a projection grating pattern, and a projection optical unit for projecting the projection grating pattern to a sample; and a detection unit including a first detection grating mask including a first detection grating pattern, a second detection grating mask including a second detection grating pattern, and a detection optical system for forming a first grating image from the projection grating pattern onto the first detection grating mask and forming a second grating image from the projection grating pattern onto the second detection grating masks. The first and second detection grating patterns at least partially overlap the first and second grating images, respectively.

Abstract: A system and a method for manipulating a beam of an Advanced Charge Controller module in different planes in an e-beam system are provided. Some embodiments of the system include a lens system configured to manipulate a beam in the tangential plane and the sagittal plane such that the beam spot is projected onto the wafer with high luminous energy. Some embodiments of the system include a lens system comprising at least two cylindrical lens.

Abstract: A sensor may be used to measure a degree of tilt of a sample. The sensor may include an apparatus having a light source, first, second, and third optical elements, a lens, and an aperture. The first optical element may supply light from the light source toward the sample, and may supply light input into the first optical element from the sample toward the second optical element. The second optical element may supply light toward first and second sensing elements. An aperture may be arranged on a focal plane of the lens. A light beam incident on the first sensing element may be a reference beam.

Abstract: An inspection apparatus for adjusting a working height for a substrate for multiple target heights is disclosed. The inspection apparatus includes a radiation source configured to provide a radiation beam and a beam splitter configured to split the radiation beam into multiple beamlets that each reflect off a substrate. Each beamlet contains light of multiple wavelengths. The inspection apparatus includes multiple light reflecting components, wherein each light reflecting component is associated with one of the beamlets reflecting off the substrate and is configured to support a different target height for the substrate by detecting a height or a levelness of the substrate based on the beamlet reflecting off the substrate.

Abstract: An optical system used in a charged particle beam inspection system. The optical system includes one or more optical lenses, and a compensation lens configured to compensate a drift of a focal length of a combination of the one or more optical lenses from a first medium to a second medium.

Abstract: An illumination unit comprising a first electromagnetic wave source including circuitry for outputting a first electromagnetic wave in a first direction to illuminate a first region of a sample; a second electromagnetic wave source including circuitry for outputting a second electromagnetic wave in a second direction substantially opposite to the first direction; and a reflector configured to reflect the second electromagnetic wave substantially in the first direction to illuminate a second region of the sample.

Abstract: An optical system used in a charged particle beam inspection system. The optical system includes one or more optical lenses, and a compensation lens configured to compensate a drift of a focal length of a combination of the one or more optical lenses from a first medium to a second medium.

Abstract: An optical system used in a charged particle beam inspection system. The optical system includes one or more optical lenses, and a compensation lens configured to compensate a drift of a focal length of a combination of the one or more optical lenses from a first medium to a second medium.

Abstract: An objective lens for forming an image of an object. The objective lens includes, sequentially from an image side to an object side, a first lens group having negative refractive power, and a second lens group having positive refractive power.

Abstract: An optical height detection system in a charged particle beam inspection system. The optical height detection system includes a projection unit including a modulated illumination source, a projection grating mask including a projection grating pattern, and a projection optical unit for projecting the projection grating pattern to a sample; and a detection unit including a first detection grating mask including a first detection grating pattern, a second detection grating mask including a second detection grating pattern, and a detection optical system for forming a first grating image from the projection grating pattern onto the first detection grating mask and forming a second grating image from the projection grating pattern onto the second detection grating masks. The first and second detection grating patterns at least partially overlap the first and second grating images, respectively.

Abstract: Disclosed is a small-diameter polarization maintaining optical fiber, which relates to the field of special optical fibers. The small-diameter polarization maintaining optical fiber comprises a quartz optical fiber (5); the periphery thereof is provided with an inner coating (6) and an outer coating (8); the interior of the quartz optical fiber (5) is provided with an optical fiber core layer (1) and a quartz cladding (2); two stress zones (4) are arranged between the optical fiber core layer (1) and the quartz cladding (2); a buffer coating (7) is arranged between the inner coating (6) and the outer coating (8); the periphery of each stress zone (4) is provided with a buffer layer (3) which is concentric with the stress zone (4); when a working wavelength of a small-diameter polarization maintaining optical fiber is 1310 nm, the attenuation thereof reaches less than 0.

Abstract: Disclosed is a small-diameter polarization maintaining optical fiber, which relates to the field of special optical fibers. The small-diameter polarization maintaining optical fiber comprises a quartz optical fiber (5); the periphery thereof is provided with an inner coating (6) and an outer coating (8); the interior of the quartz optical fiber (5) is provided with an optical fiber core layer (1) and a quartz cladding (2); two stress zones (4) are arranged between the optical fiber core layer (1) and the quartz cladding (2); a buffer coating (7) is arranged between the inner coating (6) and the outer coating (8); the periphery of each stress zone (4) is provided with a buffer layer (3) which is concentric with the stress zone (4); when a working wavelength of a small-diameter polarization maintaining optical fiber is 1310 nm, the attenuation thereof reaches less than 0.