Abstract: A charged particle beam microscope system is operated in a transmission imaging mode. During the operation, the charged particle beam microsystem directs a charged particle beam to the sample to produce images. A time series of beam tilts is applied in a pattern to the charged particle beam directed to the sample to produce a sequence of images. At least some of the images in the sequence of images are captured while the charged particle beam is transitioning between one beam tilt in the time series of beam tilts and a sequentially adjacent beam tilt in the time series of beam tilts. The pattern is configured to induce image changes between the images in the sequence of images that are indicative of optical aberrations in the charged particle beam microscope system.

Abstract: Computer-implemented methods for controlling a charged particle microscopy system include estimating a drift of a stage of the charged particle microscopy system based on an image sequence, and automatically adjusting a stage settling wait duration based on the drift estimate. Charged particle microscopy systems include an imaging system, a movement stage, and a processor and memory configured with computer-executable instructions that, when executed, cause the processor to estimate a stage settling duration of the movement stage based on an image sequence obtained with the imaging system, and automatically adjust a stage settling wait duration for the movement stage based on the stage settling duration.

Abstract: 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.

Abstract: 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.

Abstract: A charged particle beam microscope system is operated in a transmission imaging mode. During the operation, the charged particle beam microsystem directs a charged particle beam to the sample to produce images. A time series of beam tilts is applied in a pattern to the charged particle beam directed to the sample to produce a sequence of images. At least some of the images in the sequence of images are captured while the charged particle beam is transitioning between one beam tilt in the time series of beam tilts and a sequentially adjacent beam tilt in the time series of beam tilts. The pattern is configured to induce image changes between the images in the sequence of images that are indicative of optical aberrations in the charged particle beam microscope system.

Abstract: Methods include acquiring a series of images or spectra of a volume of a model sample, reconstructing a 3D image of the volume of the model sample using the series of images, constructing a 3D model of the volume of the model sample by forming a segmentation of the reconstructed 3D image and fitting one or more primitive geometrical shapes to the segmentation, acquiring test sample images or spectra, and measuring test sample critical dimensions using the constructed 3D model to guide analysis of test spectra or images. Additional methods and related systems are disclosed, optical critical dimension (OCD) methods and systems.

Abstract: Various approaches are provided for automatically focusing particle beams for SPA. In one example, a method includes determining a focus adjustment for a region of a sample to achieve a targeted defocus based on at least one defocus measurement from at least one neighboring region of the sample, and causing an acquisition of an image of the sample at the region with the focus adjustment. In this way, a targeted defocus may be achieved across regions of a sample with reduced auxiliary imaging, thereby providing increased and uniform image quality while reducing the time and thus increasing the throughput of processing.

Abstract: Computer-implemented methods for controlling a charged particle microscopy system include estimating a drift of a stage of the charged particle microscopy system based on an image sequence, and automatically adjusting a stage settling wait duration based on the drift estimate. Charged particle microscopy systems include an imaging system, a movement stage, and a processor and memory configured with computer-executable instructions that, when executed, cause the processor to estimate a stage settling duration of the movement stage based on an image sequence obtained with the imaging system, and automatically adjust a stage settling wait duration for the movement stage based on the stage settling duration.

Abstract: 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.

Abstract: 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.

Abstract: Convolutional neural networks (CNNs) of a set of CNNs are evaluated using a test set of images (electron micrographs) associated with a selected particle type. A preferred CNN is selected based on the evaluation and used for processing electron micrographs of test samples. The test set of images can be obtained by manual selection or generated using a model of the selected particle type. Upon selection of images using the preferred CNN in processing additional electron micrographs, the selected images can be added to a training set or used as an additional training set to retrain the preferred CNN. In some examples, only selected layers of the preferred CNN are retrained. In other examples, two dimensional projections of based on particles of similar structure are used for CNN training or retraining.

Abstract: 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.

Abstract: Convolutional neural networks (CNNs) of a set of CNNs are evaluated using a test set of images (electron micrographs) associated with a selected particle type. A preferred CNN is selected based on the evaluation and used for processing electron micrographs of test samples. The test set of images can be obtained by manual selection or generated using a model of the selected particle type. Upon selection of images using the preferred CNN in processing additional electron micrographs, the selected images can be added to a training set or used as an additional training set to retrain the preferred CNN. In some examples, only selected layers of the preferred CNN are retrained. In other examples, two dimensional projections of based on particles of similar structure are used for CNN training or retraining.