Abstract: The present disclosure provides an inspection system and a method of stray field mitigation. The system includes an array of electron beam columns, a first permanent magnet array, and a plurality of shielding plates. The array of electron beam columns each includes an electron source configured to emit electrons toward a stage. The first permanent magnet array is configured to condense the electrons from each electron source into an array of electron beams. The first permanent magnet array is arranged at a first end of the array of electron beam columns. The plurality of shielding plates extend across the array electron beam columns downstream of the first permanent magnet array in a direction of electron emission. The array of electron beams pass through a plurality of apertures in each of the plurality of shielding plates, which reduces stray magnetic field in a radial direction of the array of electron beams.

Abstract: The present disclosure provides an inspection system and a method of stray field mitigation. The system includes an array of electron beam columns, a first permanent magnet array, and a plurality of shielding plates. The array of electron beam columns each includes an electron source configured to emit electrons toward a stage. The first permanent magnet array is configured to condense the electrons from each electron source into an array of electron beams. The first permanent magnet array is arranged at a first end of the array of electron beam columns. The plurality of shielding plates extend across the array electron beam columns downstream of the first permanent magnet array in a direction of electron emission. The array of electron beams pass through a plurality of apertures in each of the plurality of shielding plates, which reduces stray magnetic field in a radial direction of the array of electron beams.

Abstract: These electron beam separator designs address thermally-induced beam drift in an electron-optical system. A heater coil wrapped around the beam separator unit can maintain constant power. Additional coils also can be wrapped around the beam separator in a bifilar manner, which can maintain constant power in the beam separator coils. Wien power can be determined, and then heater coil current can be determined.

Abstract: These electron beam separator designs address thermally-induced beam drift in an electron-optical system. A heater coil wrapped around the beam separator unit can maintain constant power. Additional coils also can be wrapped around the beam separator in a bifilar manner, which can maintain constant power in the beam separator coils. Wien power can be determined, and then heater coil current can be determined.

Abstract: One embodiment relates to a high-voltage electron gun including an insulator stand-off having a resistive layer. The resistive layer is at least on an interior surface of the insulator stand-off. A cathode holder is coupled to one end of the insulator 115 stand-off, and an anode is coupled to the other end. The resistive layer advantageously increases the surface breakdown field strength for the insulator stand-off and so enables a compact design for the high-voltage electron gun. Other embodiments, aspects and feature are also disclosed.

Abstract: One embodiment disclosed relates a method of detecting a patterned electron beam. The patterned electron beam is focused onto a grating with a pattern that has a same pitch as the patterned electron beam. Electrons of the patterned electron beam that pass through the grating un-scattered are detected. Another embodiment relates to focusing the patterned electron beam onto a grating with a pattern that has a second pitch that is different than a first pitch of the patterned electron beam. Electrons of the patterned electron beam that pass through the grating form a Moiré pattern that is detected using a position-sensitive detector. Other embodiments, aspects and features are also disclosed.

Abstract: One embodiment disclosed relates a method of detecting a patterned electron beam. The patterned electron beam is focused onto a grating with a pattern that has a same pitch as the patterned electron beam. Electrons of the patterned electron beam that pass through the grating un-scattered are detected. Another embodiment relates to focusing the patterned electron beam onto a grating with a pattern that has a second pitch that is different than a first pitch of the patterned electron beam. Electrons of the patterned electron beam that pass through the grating form a Moiré pattern that is detected using a position-sensitive detector. Other embodiments, aspects and features are also disclosed.