A charged particle detector may include a plurality of sensing elements formed in a substrate, wherein a sensing element of the plurality of sensing elements is formed of a first region on a first side of the substrate, and a second region on a second side of the substrate, the second side being opposite to the first side. The detector may also include a plurality of third regions formed on the second side of the substrate, the third regions including one or more circuit components. The detector may also include an array of fourth regions formed on the second side of the substrate, the array of fourth regions being between adjacent third regions.

Improved detectors for microscopy are described herein. In one aspect, an apparatus can include: a plurality of electronic units arranged in an array; a plurality of pixels, each pixel of the plurality of pixels coupled to an associated electronic unit of the plurality of electronic units, wherein a first subset of pixels of the plurality of pixels is formed from a first material, and wherein a second subset of pixels of the plurality of pixels is formed from a second material, the first material being different than the second material, and a plurality of electrical connections disposed between the plurality of electronic units and the plurality of pixels, where each electrical connection connects respective electronic units with an associated pixel.

The present disclosure describes a detector used in critical dimension scanning electron microscopes (CD-SEM) and review SEM systems. In one embodiment, the detector includes a semiconductor structure having a p-n junction and a hole through which a scanning beam is passed to a target. The detector also includes a top electrode for the p-n junction (e.g., anode or cathode) that provides an active area for detecting electrons or electromagnetic radiation (e.g., backscattering from the target). The top electrode has a doped layer and can also have a buried portion beneath the doped layer to reduce a series resistance of the top electrode without changing the active area. In another embodiment, an isolation structure can be formed in the semiconductor structure near sidewalls of the hole to electrically isolate the active area from the sidewalls. A method for forming the buried portion of the top electrode is also described.

An electron beam phase plate is provided where patterned radiation is provided to the phase plate to creates a corresponding electrical pattern, This electrical pattern provides a corresponding patterned modulation of the electron beam. Such modulation can be done in transmission or in reflection. This approach has numerous applications in electron microscopy, such as providing phase and/or amplitude shaping, aberration correction and providing phase contrast.

A hybrid arrangement of more than one electron energy conversion mechanism in an electron detector is arranged such that an image can be acquired from both energy converters so that selected high-illumination parts of the electron beam can be imaged with an indirectly coupled scintillator detector and the remainder of the image acquired with the highsensitivity/direct electron portion of the detector without readjustments in the beam position or mechanical positioning of the detector parts. Further, a mechanism is described to allow dynamically switchable or simultaneous linear and counted signal processing from each pixel on the detector so that high-illumination areas can be acquired linearly without severe dose rate limitation of counting and lowillumination regions can be acquired with counting.

A detector for use in a charged particle device for an assessment apparatus to detect charged particles from a sample, wherein the detector includes: a backscatter detector component set to a backscatter bias electric potential and configured to detect higher energy charged particles; and a secondary detector component set to a secondary bias electric potential and configured to detect lower energy charged particles, wherein there is a potential difference between the backscatter bias electric potential and the secondary bias electric potential.

A method of operating a charged particle microscope comprising the following steps: Providing a specimen on a specimen holder; Using a source to produce a beam of charged particles that is subject to beam current fluctuations; Employing a beam current sensor, located between said source and specimen holder, to intercept a part of the beam and produce an intercept signal proportional to a current of the intercepted part of the beam, the beam current sensor comprising a hole arranged to pass a beam probe with an associated probe current; Scanning said probe over the specimen, thereby irradiating the specimen with a specimen current, with a dwell time associated with each scanned location on the specimen; Using a detector to detect radiation emanating from the specimen in response to irradiation by said probe, and producing an associated detector signal; Using said intercept signal as input to a compensator to suppress an effect of said current fluctuations in said detector signal,
wherein: The beam current sensor is configured as a semiconductor device with a sensing layer that is oriented toward the source, in which: Each charged particle of said intercepted part of the beam generates electron/hole pairs in said sensing layer; Generated electrons are drawn to an anode of the semiconductor device; Generated holes are drawn to a cathode of the semiconductor device, thereby producing said intercept signal.

A detector for a charged particle beam device includes a substrate, a number of first sensor devices provided on the substrate, wherein the first sensor devices are structured to be sensitive to and generate a first signal in response to electrons ejected by a specimen, and a number of second sensor devices provided on the substrate, wherein the second sensor devices are structured to be sensitive to and generate a second signal in response to photons emitted by the specimen. Also, a photon detector wherein each of the photon sensor devices is structured to be sensitive to and generate a signal in response to photons emitted by the specimen, and wherein each of the photon sensor devices comprises a MultiPixel Photon Counter device. Further, a method of imaging a specimen using a charged particle beam device uses beam blanking and determination of estimated a decay time constants.

A silicon photomultiplier (SiPM) device is provided with a SiPM matrix fabricated on a substrate, a bias power supply connected to the SiPM matrix, and a compensation circuit coupled to the bias power supply. The bias power supply provides a bias voltage to the SiPM matrix. The compensation circuit can adjust the bias voltage applied to the SiPM matrix in response to temperature changes at the substrate. The compensation circuit includes a resistor fabricated on the substrate with the SiPM matrix. The resistor can have a resistance that varies in response to temperature changes at the substrate.

Quantitative Secondary Electron Detection (QSED) using the array of solid state devices (SSD) based electron-counters enable critical dimension metrology measurements in materials such as semiconductors, nanomaterials, and biological samples (FIG. 3). Methods and devices effect a quantitative detection of secondary electrons with the array of solid state detectors comprising a number of solid state detectors. An array senses the number of secondary electrons with a plurality of solid state detectors, counting the number of secondary electrons with a time to digital converter circuit in counter mode.