Abstract: Systems and methods of observing a sample using a charged-particle beam apparatus in voltage contrast mode are disclosed. The charged-particle beam apparatus comprises a charged-particle source, an optical source, a charged-particle detector configured to detect charged particles, and a controller having circuitry configured to apply a first signal to cause the optical source to generate the optical pulse, apply a second signal to the charged-particle detector to detect the second plurality of charged particles, and adjust a time delay between the first and the second signals. In some embodiments, the controller having circuitry may be further configured to acquire a plurality of images of a structure, to determine an electrical characteristic of the structure based on the rate of gray level variation of the plurality of images of the structure, and to simulate, using a model, a physical characteristic of the structure based on the determined electrical characteristic.

Abstract: A charged particle beam apparatus for inspecting a sample is provided. The apparatus includes a pixelized electron detector to receive signal electrons generated in response to an incidence of an emitted charged particle beam onto the sample. The pixelized electron detector includes multiple pixels arranged in a grid pattern. The multiple pixels may be configured to generate multiple detection signals, wherein each detection signal corresponds to the signal electrons received by a corresponding pixel of the pixelized electron detector. The apparatus further includes a controller includes circuitry configured to determine a topographical characteristic of a structure within the sample based on the detection signals generated by the multiple pixels, and identifying a defect within the sample based on the topographical characteristic of the structure of the sample.

Abstract: A method for determining a probabilistic model configured to predict a characteristic (e.g., defects, CD, etc.) of a pattern of a substrate subjected to a patterning process. The method includes obtaining a spatial map of a distribution of a residue corresponding to a characteristic of the pattern on the substrate, determining a zone of the spatial map based on a variation of the distribution of the residue within the spatial map, and determining the probabilistic model based on the zone and the distribution of the residue values or the values of the characteristic of the pattern on the substrate within the zone.

Abstract: A method of topography determination, the method including: obtaining a first focus value derived from a computational lithography model modeling patterning of an unpatterned substrate or derived from measurements of a patterned layer on an unpatterned substrate; obtaining a second focus value derived from measurement of a substrate having a topography; and determining a value of the topography from the first and second focus values.

Abstract: A method including obtaining verified values of a characteristic of a plurality of patterns on a substrate produced by a device manufacturing process; obtaining computed values of the characteristic using a non-probabilistic model; obtaining values of a residue of the non-probabilistic model based on the verified values and the computed values; and obtaining an attribute of a distribution of the residue based on the values of the residue. Also disclosed herein are methods of computing a probability of defects on a substrate produced by the device manufacturing process, and of obtaining an attribute of a distribution of the residue of a non-probabilistic model.

Abstract: A method including: determining a value of a characteristic of a patterning process or a product thereof, at a current value of a processing parameter; determining whether a termination criterion is met by the value of the characteristic; if the termination criterion is not met, determining a new value of the processing parameter from the current value of the processing parameter and a prior value of the processing parameter, and setting the current value to the new value and repeating the determining steps; and if the termination criterion is met, providing the current value of the processing parameter as an approximation of a value of the processing parameter at which the characteristic has a target value.

Abstract: A method of topography determination, the method including: obtaining a first focus value derived from a computational lithography model modeling patterning of an unpatterned substrate or derived from measurements of a patterned layer on an unpatterned substrate; obtaining a second focus value derived from measurement of a substrate having a topography; and determining a value of the topography from the first and second focus values.

Abstract: A method including obtaining verified values of a characteristic of a plurality of patterns on a substrate produced by a device manufacturing process; obtaining computed values of the characteristic using a non-probabilistic model; obtaining values of a residue of the non-probabilistic model based on the verified values and the computed values; and obtaining an attribute of a distribution of the residue based on the values of the residue. Also disclosed herein are methods of computing a probability of defects on a substrate produced by the device manufacturing process, and of obtaining an attribute of a distribution of the residue of a non-probabilistic model.

Abstract: A method of topography determination, the method including: obtaining a first focus value derived from a computational lithography model modeling patterning of an unpatterned substrate or derived from measurements of a patterned layer on an unpatterned substrate; obtaining a second focus value derived from measurement of a substrate having a topography; and determining a value of the topography from the first and second focus values.

Abstract: A method for determining a probabilistic model configured to predict a characteristic (e.g., defects, CD, etc.) of a pattern of a substrate subjected to a patterning process. The method includes obtaining a spatial map of a distribution of a residue corresponding to a characteristic of the pattern on the substrate, determining a zone of the spatial map based on a variation of the distribution of the residue within the spatial map, and determining the probabilistic model based on the zone and the distribution of the residue values or the values of the characteristic of the pattern on the substrate within the zone.

Abstract: A method of topography determination, the method including: obtaining a first focus value derived from a computational lithography model modeling patterning of an unpatterned substrate or derived from measurements of a patterned layer on an unpatterned substrate; obtaining a second focus value derived from measurement of a substrate having a topography; and determining a value of the topography from the first and second focus values.

Abstract: A method including: determining a value of a characteristic of a patterning process or a product thereof, at a current value of a processing parameter; determining whether a termination criterion is met by the value of the characteristic; if the termination criterion is not met, determining a new value of the processing parameter from the current value of the processing parameter and a prior value of the processing parameter, and setting the current value to the new value and repeating the determining steps; and if the termination criterion is met, providing the current value of the processing parameter as an approximation of a value of the processing parameter at which the characteristic has a target value.

Abstract: Ultrafine dimensions are accurately and efficiently formed in a target layer using a spacer lithographic technique comprising forming a first mask pattern, forming a cross-linkable layer over the first mask pattern, forming a cross-linked spacer between the first mask pattern and cross-linkable layer, removing the cross-linkable layer, cross-linked spacer from the upper surface of the first mask pattern and the first mask pattern to form a second mask pattern comprising remaining portions of the cross-linked spacer, and etching using the second mask pattern to form an ultrafine pattern in the underlying target layer.

Abstract: Precise and repeatable alignment performance using asymmetric illumination is achieved by properly structuring, as by segmenting, an alignment mark on a reticle of a photolithographic exposure apparatus as a function of the type of asymmetric illumination, thereby improving resolution and repeatability of an alignment mark formed on a target substrate. Embodiments include double exposure techniques using dipole illumination with an angularly segmented alignment mark, e.g., at 45°, such that the first-order diffracted light is sent at 45° from the initial position of the dipole illumination.

Abstract: A composite exposure image is formed on a photoresist layer by applying a light beam through a reticle to form a first exposure image thereon, and thereafter, while maintaining the position of the reticle with respect to the photoresist layer, again applying a light beam through the reticle to form a second exposure image thereon. By adjusting the light beam differently in focus and intensity for each exposure, the combination of first and second exposure images form a pattern on the photoresist of lesser pitch than can be produced from a single exposure. The formation of a single pattern in the single resist layer from the two exposures avoids misalignment problems and eliminates the need for double exposure of a plurality of resist layers.

Abstract: Ultrafine dimensions are accurately and efficiently formed in a target layer using a spacer lithographic technique comprising forming a first mask pattern, forming a cross-linkable layer over the first mask pattern, forming a cross-linked spacer between the first mask pattern and cross-linkable layer, removing the cross-linkable layer, cross-linked spacer from the upper surface of the first mask pattern and the first mask pattern to form a second mask pattern comprising remaining portions of the cross-linked spacer, and etching using the second mask pattern to form an ultrafine pattern in the underlying target layer.

Abstract: A reflective mask (e.g., an EUV reflective mask) and a method of making such a mask are disclosed. The mask includes an absorbent substrate and a reflective coating overlying the substrate. The reflective coating is patterned to include a circuit design that is to be transferred onto one or more wafers, and more particularly onto one or more die on the wafers, during semiconductor fabrication processing. The mask includes no other radiation absorbent material, and the occurrence and severity of dead zones, which commonly occur in conventional reflective masks and which degrade the fidelity of pattern transfers, are thereby mitigated. A methodology for inspecting the mask via the transmission of visible, UV or deep-UV radiation through the mask is also disclosed.

Abstract: A methodology for forming a reflective mask is disclosed. The mask facilitates accurate pattern transfers as a substantially defect free reflective coating is formed therein. The mask can generally be formed according to four main steps, for example, which include depositing a reflective coating (e.g., formed of multiple layers) over a substrate, patterning and then inspecting for defects a masking material formed over the reflective coating, correcting such defects and finally patterning the reflective coating with the patterned masking material serving as a guide.

Abstract: An optical tool includes a tool body that is transparent to light. Pluralities of parallel opaque lines on the body form a first outline in the shape of the square, and a second outline in the shape of a square which is centrally located relative to and within the first-mentioned square. Each pair of adjacent parallel lines has therebetween a first region that allows transmission of light therethrough without changing phase thereof, and a second region alongside the first region that allows transmission of light therethrough while shifting the phase thereof by 90°. The phase shifting and non-phase shifting regions are positioned so that the images of the outlines provided by a lens on an object shit in position a substantial amount as the distance between the lens and the object is changed.

Abstract: An optical monitor includes a body having a first plurality of parallel, substantially opaque, spaced apart lines thereon, and the second plurality of parallel, substantially opaque, spaced apart lines thereon, with a relatively small angle between the first and second pluralities of lines. A an image of the lines of the first plurality thereof is provided on the semiconductor body, upon relative movement of the monitor toward and away from the semiconductor body, the line images move relative to the semiconductor body. The images of the lines of the second plurality thereof provided on the semiconductor body move in a different manner upon relative movement if the monitor toward and away from the semiconductor body: The moiré fringe formed on the semiconductor body from images of the first and second plurality of lines during such movement is analyzed in order to achieve proper focus of the image on the semiconductor body.