A sample holder retains a sample and can continuously rotate the sample in a single direction while the sample is exposed to a charged particle beam (CPB) or other radiation source. Typically, the CPB is strobed to produce a series of CPB images at random or arbitrary angles of rotation. The sample holder can rotate more than one complete revolution of the sample. The CPB images are used in tomographic reconstruction, and in some cases, relative rotation angles are used in the reconstruction, without input of an absolute rotation angle.

Embodiments consistent with the disclosure herein include methods and a multi-beam apparatus configured to emit charged-particle beams for imaging a top and side of a structure of a sample, including: a deflector array including a first deflector and configured to receive a first charged-particle beam and a second charged-particle beam; a blocking plate configured to block one of the first charged-particle beam and the second charged-particle beam; and a controller having circuitry and configured to change the configuration of the apparatus to transition between a first mode and a second mode. In the first mode, the deflector array directs the second charged-particle beam to the top of the structure, and the blocking plate blocks the first charged-particle beam. And in the second mode, the first deflector deflects the first charged-particle beam to the side of the structure, and the blocking plate blocks the second charged-particle beam.

The disclosure relates to a method of imaging a specimen using a transmission charged particle microscope, said method comprising providing a specimen, and providing a charged particle beam and directing said charged particle beam onto said specimen for generating a flux of charged particles transmitted through the specimen. The method comprises the step of generating and recording a first energy filtered flux of charged particles transmitted through the specimen, wherein said first energy filtered flux of charged particles substantially consists of non-scattered and elastically scattered charged particles. The method as disclosed herein comprises the further step of generating and recording a second energy filtered flux of charged particles transmitted through the specimen, wherein said second energy filtered flux of charged particles substantially consists of inelastically scattered charged particles. Said first and second recorded energy filtered flux are then used for imaging said specimen with increased contrast.

A computer-implemented method of processing image data according to the present disclosure comprises: receiving the image data, wherein the image data is scanning transmission charged-particle microscope (STCPM) image data representing a STCPM scan obtained at a first focus depth; and processing a system of equations expressing the image data as a sum of contributions from a plurality of slices of the sample at a plurality of focus depths, wherein each equation of the system of equations relates at least a portion of the image data to: at least one of a plurality of contrast transfer functions of the STCPM, each contrast transfer function of the STCPM being determined at a different respective focus depth; and at least one set of unknown objects of the STCPM, each unknown object in a set being at a different respective focus depth. The step of processing comprises solving the system of equations to obtain at least one of the plurality of unknown objects of the STCPM.

A sample holder retains a sample and can continuously rotate the sample in a single direction while the sample is exposed to a charged particle beam (CPB) or other radiation source. Typically, the CPB is strobed to produce a series of CPB images at random or arbitrary angles of rotation. The sample holder can rotate more than one complete revolution of the sample. The CPB images are used in tomographic reconstruction, and in some cases, relative rotation angles are used in the reconstruction, without input of an absolute rotation angle.

Methods include providing a multi-pillar sample including at least a first pillar and a second pillar parallel with the first pillar, directing a charged particle beam to the first pillar, imaging the first pillar at a plurality of rotational positions by rotating the multi-pillar sample about a first pillar axis of the first pillar, directing the charged particle beam to the second pillar, and imaging the second pillar at a plurality of rotational positions by rotating the multi-pillar sample about a second pillar axis of the second pillar. Related apparatus for performing disclosed methods are disclosed. Multi-pillar samples are also disclosed.

Linear fiducials including notches or chevrons with known angles relative to each other are formed such that each branch of a chevron appears in a cross-sectional face of the sample as a distinct structure. Therefore, when imaging the cross-section face during the cross-sectioning operation, the distance between the identified structures allows unique identification of the position of the cross-section plane along the Z axis. Then a direct measurement of the actual position of each slice can be calculated, allowing for dynamic repositioning to account for drift in the plane of the sample and also dynamic adjustment of the forward advancement rate of the FIB to account for variations in the sample, microscope, microscope environment, etc. that contributes to drift. An additional result of this approach is the ability to dynamically calculate the actual thickness of each acquired slice as it is acquired.

Systems and methods for image enhancement are disclosed. A method for enhancing an image may include acquiring a scanning electron microscopy (SEM) image. The method may also include simulating diffused charge associated with a position of the SEM image. The method may further include providing an enhanced SEM image based on the SEM image and the diffused charge.

An image processor includes an image generator configured to generate corresponding image data corresponding to first microscopic image data obtained under a first observation condition, based on second microscopic image data and third microscopic image data obtained under a second observation condition, and an image output unit configured to output the corresponding image data. The corresponding image data may be image data corresponding to a first focal plane from which the first microscopic image data are obtained, and wherein the second microscopic image data and the third microscopic image data may be image data on a second focal plane and a third focal plane, respectively, which are different from the first focal plane.

A metrology method for use in determining one or more parameters of a patterned structure, the method including providing raw measured TEM image data, TEM.sub.meas, data indicative of a TEM measurement mode, and predetermined simulated TEM image data including data indicative of one or more simulated TEM images of a structure similar to the patterned structure under measurements and a simulated weight map including weights assigned to different regions in the simulated TEM image corresponding to different features of the patterned structure, performing a fitting procedure between the raw measured TEM image data and the predetermined simulated TEM image data and determining one or more parameters of the structure from the simulated TEM image data corresponding to a best fit condition.