Abstract: A metrology system includes a controller coupled to a detector to generate a detection signal based on the reflection of an illumination beam from a multilayer film stack. The multilayer film stack may include one or more zones with a repeating pattern of two or more materials. The controller may generate a model of reflection of the illumination beam by modeling the zones as thick films having zone thicknesses and effective permittivity values using an effective medium model relating the effective permittivity values of the zones to permittivity values and volume fractions of constituent materials. The controller may further determine values of the zone thicknesses and the volume fractions using a regression of the detection signal based on the effective medium model and further determine average thickness values of the constituent materials based on the number of films, the zone thicknesses, the volume fractions, and the effective permittivity values.

Abstract: A metrology system includes a controller coupled to a detector to generate a detection signal based on the reflection of an illumination beam from a multilayer film stack. The multilayer film stack may include one or more zones with a repeating pattern of two or more materials. The controller may generate a model of reflection of the illumination beam by modeling the zones as thick films having zone thicknesses and effective permittivity values using an effective medium model relating the effective permittivity values of the zones to permittivity values and volume fractions of constituent materials. The controller may further determine values of the zone thicknesses and the volume fractions using a regression of the detection signal based on the effective medium model and further determine average thickness values of the constituent materials based on the number of films, the zone thicknesses, the volume fractions, and the effective permittivity values.

Abstract: A spectrometer for tailored spectral sampling includes a dispersive element for spatially dispersing a spectrum of a light beam, a detector including a plurality of pixels distributed along a sampling direction, and a spectrum reshaping element including at least one of a reflective surface or a transmissive surface for reshaping the spatially-dispersed spectrum of the light beam from the dispersive element along the sampling direction to provide a selected distribution of the spectrum to the detector. The detector may spatially sample the spectrum of incident light with the plurality of pixels at selected spectral intervals based on the selected distribution of the spectrum.

Abstract: A spectrometer for tailored spectral sampling includes a dispersive element for spatially dispersing a spectrum of a light beam, a detector including a plurality of pixels distributed along a sampling direction, and a spectrum reshaping element including at least one of a reflective surface or a transmissive surface for reshaping the spatially-dispersed spectrum of the light beam from the dispersive element along the sampling direction to provide a selected distribution of the spectrum to the detector. The detector may spatially sample the spectrum of incident light with the plurality of pixels at selected spectral intervals based on the selected distribution of the spectrum.

Abstract: One embodiment relates to a method of real-time three-dimensional electron beam imaging of a substrate surface. A primary electron beam is scanned over the substrate surface causing electrons to be emitted therefrom. The emitted electrons are simultaneously detection using a plurality of at least two off-axis sensors so as to generate a plurality of image data frames, each image data frame being due to electrons emitted from the substrate surface at a different view angle. The plurality of image data frames are automatically processed to generate a three-dimensional representation of the substrate surface. Multiple views of the three-dimensional representation are then displayed. Other embodiments, aspects and features are also disclosed.

Abstract: One embodiment relates to a method for metrology using an electron beam apparatus. At least one region of interest is selected in a field of view at a magnification level. Scanning parameters are determined to selectively scan over the at least one regions of interest under the magnification level of the field of view. The electron beam is selectively scanned over the at least one region of interest to capture image data from the at least one region of interest while maintaining the magnification level of the field of view. Other embodiments are also disclosed.

Abstract: One embodiment disclosed relates to a method for automated focusing of an electron image. An EF cut-off voltage is determined. In compensation for a change in the EF cut-off voltage, a focusing condition is adjusted. Adjusting the focusing condition may comprise, for example, adjusting a wafer bias voltage in correspondence to the change in cut-off voltage. Another embodiment disclosed relates to a method for automated focusing of an electron image in a scanning electron imaging apparatus. A focusing condition of a primary electron beam in a first image plane is varied so as to maximize an intensity of a secondary electron beam through an aperture in a second image plane.