Scanning particle beam instrument
First Claim
1. A scanning particle beam instrument that includes a scanner, a radiation detector and a DC amplifier, the scanner being operable to scan a beam of charged particles relative to a specimen, the radiation detector being operable to generate a signal representative of an intensity of radiation resulting from interaction of the beam and a specimen, and the DC amplifier being operable to amplify the signal generated by the radiation detector to produce a video signal, wherein the instrument also includes a controller operable to so direct the beam relative to a specimen, or to determine when the beam is so directed relative to a specimen, that an actual video signal produced by the DC amplifier may be compared with a desired video signal, to compare an actual video signal and a desired video signal, and to adjust a DC offset of the DC amplifier so as to reduce a difference between the actual video signal and the desired video signal.
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Accused Products
Abstract
A scanning particle beam instrument is provided, the instrument including a scanner, a radiation detector and a DC amplifier, the DC amplifier being operable to amplify a signal generated by the radiation detector to produce a video signal, the instrument further including a controller operable to so direct the beam relative to a specimen, or to determine when the beam is so directed relative to a specimen, that an actual video signal produced by the DC amplifier may be compared with a desired video signal, to compare actual and desired video signals and to adjust a DC offset of the DC amplifier so as to reduce a difference between the signals. Also provided is a method of producing a video signal using such an instrument.
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Citations
21 Claims
- 1. A scanning particle beam instrument that includes a scanner, a radiation detector and a DC amplifier, the scanner being operable to scan a beam of charged particles relative to a specimen, the radiation detector being operable to generate a signal representative of an intensity of radiation resulting from interaction of the beam and a specimen, and the DC amplifier being operable to amplify the signal generated by the radiation detector to produce a video signal, wherein the instrument also includes a controller operable to so direct the beam relative to a specimen, or to determine when the beam is so directed relative to a specimen, that an actual video signal produced by the DC amplifier may be compared with a desired video signal, to compare an actual video signal and a desired video signal, and to adjust a DC offset of the DC amplifier so as to reduce a difference between the actual video signal and the desired video signal.
- 16. A method of generating a video signal using a scanning particle beam instrument, the method comprising the steps of directing a beam of charged particles towards a specimen, scanning the beam relative to the specimen, detecting radiation emitted by or reflected from the specimen as a result of scanning by the beam to generate a signal representative of an intensity of the radiation, and amplifying by means of a DC amplifier the signal representative of the intensity of the radiation to produce an actual video signal, wherein the method further comprises the steps of so directing the beam relative to the specimen, or determining when the beam is so directed relative to the specimen, that the actual video signal produced by the DC amplifier may be compared with a desired video signal, comparing an actual video signal and a desired video signal, and adjusting a DC offset of the DC amplifier so as to reduce a difference between the actual video signal and the desired video signal.
Specification