An ion collector includes a plurality of segments and a plurality of integrators. The plurality of segments are physically separated from one another and spaced around a substrate support. Each of the segments includes a conductive element that is designed to conduct a current based on ions received from a plasma. Each of the plurality of integrators is coupled to a corresponding conductive element. Each of the plurality of integrators is designed to determine an ion distribution for a corresponding conductive element based, at least in part, on the current conducted at the corresponding conductive element. An example benefit of this embodiment includes the ability to determine how uniform the ion distribution is across a wafer being processed by the plasma.

An ion collector includes a plurality of segments and a plurality of integrators. The plurality of segments are physically separated from one another and spaced around a substrate support. Each of the segments includes a conductive element that is designed to conduct a current based on ions received from a plasma. Each of the plurality of integrators is coupled to a corresponding conductive element. Each of the plurality of integrators is designed to determine an ion distribution for a corresponding conductive element based, at least in part, on the current conducted at the corresponding conductive element. An example benefit of this embodiment includes the ability to determine how uniform the ion distribution is across a wafer being processed by the plasma.

There is provided an electron microscope capable of producing good images by reducing contrast nonuniformity. The electron microscope (1) includes: an electron beam source (11) for producing an electron beam; a noise cancelling aperture (12) and an amplifier (42) for detecting a part of the electron beam; an effective value computing circuit (44) and a low frequency cut-off circuit (46) for extracting a DC component of an effective value of a detection signal emanating from the amplifier (42); an image detector (15) for detecting a signal produced in response to impingement of the beam on a sample (A); a preamplifier circuit (20) and an amplifier circuit (30); a divider circuit (54) for performing a division of the output signal (X) from the amplifier circuit (30) by the output signal (Y) from the amplifier circuit (42) and producing a quotient signal indicative of the result of the decision (X/Y); and a multiplier circuit (58) for multiplying the quotient signal by a signal (Z) extracted by the low frequency cut-off circuit (46).

There is provided an electron microscope capable of producing good images by reducing contrast nonuniformity. The electron microscope (1) includes: an electron beam source (11) for producing an electron beam; a noise cancelling aperture (12) and an amplifier (42) for detecting a part of the electron beam; an effective value computing circuit (44) and a low frequency cut-off circuit (46) for extracting a DC component of an effective value of a detection signal emanating from the amplifier (42); an image detector (15) for detecting a signal produced in response to impingement of the beam on a sample (A); a preamplifier circuit (20) and an amplifier circuit (30); a divider circuit (54) for performing a division of the output signal (X) from the amplifier circuit (30) by the output signal (Y) from the amplifier circuit (42) and producing a quotient signal indicative of the result of the decision (X/Y); and a multiplier circuit (58) for multiplying the quotient signal by a signal (Z) extracted by the low frequency cut-off circuit (46).

In accordance with an embodiment, a signal processing method includes scanning a pattern on a substrate with a charged particle beam, detecting secondary charged particles emitted from the substrate by using a detector, outputting a signal, and filtering the signal. The detector is separated or divided into a plurality of regions, and the secondary charged particles are detected separately in each region of the detector. Intensity of the filtering is defined in dependence on a function f() of an angle between a reference axis and a direction along which the secondary charged particles enter a detector plane. The reference axis is an arbitrary direction in a plane parallel to a surface of the substrate.

An apparatus includes an electron source coupled to provide an electron beam, a beam deflector arranged to provide a pulsed electron beam from the electron beam, a detector arranged to receive the pulsed electron beam after transmitting through a sample, and a controller coupled to control at least the beam deflector and the detector, the controller coupled to or including code that, when executed by the controller, causes the apparatus to establish the pulsed electron beam with pulse characteristics based on control of at least the beam deflector, wherein an illumination window is formed based on the pulse characteristics, the illumination window being a time frame when the sample is illuminated with a pulse of the pulsed electron beam, and to form a detection window for the detector and synchronize the detection window in relation to the illumination window, wherein detection events occurring in the detection window form the basis of an image, wherein the detection window determines a time frame when the detector converts the pulse of the pulsed electron beam transmitted through the sample to an electron induced signal.

An ion collector includes a plurality of segments and a plurality of integrators. The plurality of segments are physically separated from one another and spaced around a substrate support. Each of the segments includes a conductive element that is designed to conduct a current based on ions received from a plasma. Each of the plurality of integrators is coupled to a corresponding conductive element. Each of the plurality of integrators is designed to determine an ion distribution for a corresponding conductive element based, at least in part, on the current conducted at the corresponding conductive element. An example benefit of this embodiment includes the ability to determine how uniform the ion distribution is across a wafer being processed by the plasma.

An ion collector includes a plurality of segments and a plurality of integrators. The plurality of segments are physically separated from one another and spaced around a substrate support. Each of the segments includes a conductive element that is designed to conduct a current based on ions received from a plasma. Each of the plurality of integrators is coupled to a corresponding conductive element. Each of the plurality of integrators is designed to determine an ion distribution for a corresponding conductive element based, at least in part, on the current conducted at the corresponding conductive element. An example benefit of this embodiment includes the ability to determine how uniform the ion distribution is across a wafer being processed by the plasma.