Abstract: A variable illumination angle inspection system is provided, including a light source providing a light beam and a scanner imparting scanning deflection to the light beam to provide a scanning beam approaching a substrate at a first angle. A deflection element is selectively insertable into an optical path of the scanning beam to deflect the scanning beam so as to cause the scanning beam to approach the substrate at a second angle.

Abstract: An area of a substrate is imaged with and without heating, to obtain a hot image and a cold image respectively. The hot and cold images are compared with one another to identify one or more locations as being defective, e.g. if the result of comparison at one location differs significantly relative to other locations. The comparison results in all locations form a differential image, and in several embodiments a number of differential images are obtained by repeatedly heating, imaging and comparing. In such embodiments, multiple differential images are averaged at each location, to improve the signal to noise ratio. Pump and probe lasers may be used for heating and for illumination respectively, or alternatively a single laser may be employed to generate both pump and probe beams.

Abstract: An optical inspection apparatus and method is provided that utilizes both linear and nonlinear optical phenomena to detect defects. Embodiments include irradiating a portion of the surface of an article, such as a semiconductor device, with a light beam, such as a scanning laser at an incident wavelength. The light emanating from the irradiated surface portion is then separated into light at the incident wavelength and light at one or more predetermined non-incident wavelengths, as by a diffraction grating, prism or filters. The light at the incident and nonincident wavelengths is sent to separate detectors, such as photomultipliers (PMT), which respectively convert the detected linear optical phenomena (representing, e.g., surface topography) into an electrical signal, and the detected nonlinear optical phenomena, such as fluorescence, Raman scattering and/or second harmonic generation, into electrical signals representing, e.g., chemical composition and material interfaces.

Abstract: Apparatus for spatial filtering includes a Fourier lens, adapted to collect radiation emitted from a point and to separate the collected radiation into spatial components in a Fourier plane of the lens, and a programmable spatial filter, positioned at the Fourier plane. An image sensor is optically coupled to capture an image of the spatial components of the collected radiation in the Fourier plane, while the components are incident on the filter. A filter controller is coupled to receive and analyze the image captured by the image sensor and, responsive thereto, to control the spatial filter so as to block one or more of the spatial components.

Abstract: Apparatus for spatial filtering includes a Fourier lens, adapted to collect radiation emitted from a point and to separate the collected radiation into spatial components in a Fourier plane of the lens, and a programmable spatial filter, positioned at the Fourier plane. An image sensor is optically coupled to capture an image of the spatial components of the collected radiation in the Fourier plane, while the components are incident on the filter. A filter controller is coupled to receive and analyze the image captured by the image sensor and, responsive thereto, to control the spatial filter so as to block one or more of the spatial components.

Abstract: An optical inspection apparatus and method is provided that utilizes both linear and nonlinear optical phenomena to detect defects. Embodiments include irradiating a portion of the surface of an article, such as a semiconductor device, with a light beam, such as a scanning laser at an incident wavelength. The light emanating from the irradiated surface portion is then separated into light at the incident wavelength and light at one or more predetermined non-incident wavelengths, as by a diffraction grating, prism or filters. The light at the incident and nonincident wavelengths is sent to separate detectors, such as photomultipliers (PMT), which respectively convert the detected linear optical phenomena (representing, e.g., surface topography) into an electrical signal, and the detected nonlinear optical phenomena, such as fluorescence, Raman scattering and/or second harmonic generation, into electrical signals representing, e.g., chemical composition and material interfaces.