The present disclosure relates to a method of operating an SPM system including a landing procedure. The landing procedure comprises a first landing stage including a first translation over a first actuation distance by a coarse translation means to bring a probe tip held by an SPM head from an initial separation from a substrate to be probed to a second, more proximal, separation as defined by a characteristic transitional response of the probe tip in proximity to the substrate. Following the first stage a second translation is applied, over a second actuation distance by a fine translation means under feedback control to bring the probe tip to a working separation. Prior to applying the first (coarse) actuation distance an initial optical distance is determined which is indicative of the initial separation, using a detector, preferably a mark sensor. The measured initial optical distance is related to a reference distance so as to determine a deviation. The first actuation distance corresponds the reference distance and the deviation. The disclosure also relates to an SPM system and software product arranged to implement the landing method.

A method of calibrating a topography metrology instrument using a calibration reference, which includes a substrate and a plurality of bi-layer stacks. Each bi-layer stack includes a plurality of bi-layer steps. At least one bi-layer step of the plurality of bi-layer steps includes two materials. The at least one bi-layer step of the plurality of bi-layer steps includes an etch stop layer and a bulk layer. The calibration reference includes a calibration reference step profile includes a plurality of predetermined bi-layer stack heights. The calibration reference step profile and the predetermined bi-layer stack heights are measured using a topography metrology instrument. The topography metrology instrument is calibrated based on the measured calibration reference step profile and the measured bi-layer stack heights.

A method of calibrating a topography metrology instrument using a calibration reference, which includes a substrate and a plurality of bi-layer stacks. Each bi-layer stack includes a plurality of bi-layer steps. At least one bi-layer step of the plurality of bi-layer steps includes two materials. The at least one bi-layer step of the plurality of bi-layer steps includes an etch stop layer and a bulk layer. The calibration reference includes a calibration reference step profile includes a plurality of predetermined bi-layer stack heights. The calibration reference step profile and the predetermined bi-layer stack heights are measured using a topography metrology instrument. The topography metrology instrument is calibrated based on the measured calibration reference step profile and the measured bi-layer stack heights.

A method for automatically calibrating a feedback system, comprising: receiving one or more input parameters associated with a feedback system; applying the one or more input parameters to a model of the feedback system; deriving one or more feedback parameters for the feedback system from the model by: optimizing the model for the feedback parameters, and applying a noise characteristic of the feedback system to the model; and automatically tuning the feedback system using the one or more derived feedback parameters.

A method for automatically calibrating a feedback system, comprising: receiving one or more input parameters associated with a feedback system; applying the one or more input parameters to a model of the feedback system; deriving one or more feedback parameters for the feedback system from the model by: optimizing the model for the feedback parameters, and applying a noise characteristic of the feedback system to the model; and automatically tuning the feedback system using the one or more derived feedback parameters.

Systems and methods are disclosed that remove noise from roughness measurements to determine roughness of a feature in a pattern structure. In one embodiment, a method for determining roughness of a feature in a pattern structure includes generating, using an imaging device, a set of one or more images, each including measured linescan information that includes noise. The method also includes detecting edges of the features within the pattern structure of each image without filtering the images, generating a biased power spectral density (PSD) dataset representing feature geometry information corresponding to the edge detection measurements, evaluating a high-frequency portion of the biased PSD dataset to determine a noise model for predicting noise over all frequencies of the biased PSD dataset, and subtracting the noise predicted by the determined noise model from a biased roughness measure to obtain an unbiased roughness measure.

The invention is directed at a fiducial marker design, a fiducial marker, a scanning probe microscopy device and a method of calibrating a position of a probe tip. The fiducial marker design may be used as a fiducial marker for providing a positioning reference, and comprises at least one first reference pattern including at least one first reference element for enabling determination of a relative position of the fiducial marker with respect to a first sensor. The first sensor is configured for operating at a first scale of dimension. The fiducial marker further comprises a second reference pattern, which comprises a regular arrangement of markings, structured or shaped such as to encode therein surface coordinate information. This enables determination of a relative position of each marking with respect to a second sensor configured for operating at a second scale of dimension smaller than the first scale of dimension.

The invention is directed at a fiducial marker design, a fiducial marker, a scanning probe microscopy device and a method of calibrating a position of a probe tip. The fiducial marker design may be used as a fiducial marker for providing a positioning reference, and comprises at least one first reference pattern including at least one first reference element for enabling determination of a relative position of the fiducial marker with respect to a first sensor. The first sensor is configured for operating at a first scale of dimension. The fiducial marker further comprises a second reference pattern, which comprises a regular arrangement of markings, structured or shaped such as to encode therein surface coordinate information. This enables determination of a relative position of each marking with respect to a second sensor configured for operating at a second scale of dimension smaller than the first scale of dimension.

A method of removing a defect of a mask may include generating a probe profile, the probe profile including characteristics of a probe of an atomic force microscope (AFM); generating a design-based reference image of a defect area by applying the probe profile to a design image of the defect area of the mask including a location of the defect; obtaining an AFM image of the defect area by scanning the defect area of the mask using the probe of the AFM; recognizing the defect as a recognized defect by comparing the AFM image of the defect area with the design-based reference image; and removing the recognized defect using the probe of the AFM.

A method of removing a defect of a mask may include generating a probe profile, the probe profile including characteristics of a probe of an atomic force microscope (AFM); generating a design-based reference image of a defect area by applying the probe profile to a design image of the defect area of the mask including a location of the defect; obtaining an AFM image of the defect area by scanning the defect area of the mask using the probe of the AFM; recognizing the defect as a recognized defect by comparing the AFM image of the defect area with the design-based reference image; and removing the recognized defect using the probe of the AFM.