Abstract: A scanning electron microscope having an electron column positioned to direct an electron beam onto a sample the electron column having a vacuum enclosure; an electron source; and an electromagnetic objective lens positioned within the vacuum enclosure, the electromagnetic objective lens including a housing having an entry aperture at top surface thereof and an exit aperture at bottom thereof; an electromagnetic coil radially positioned within the housing; a light objective positioned within the housing and comprising a concave minor having a first axial aperture and a convex minor having a second axial aperture; an electron beam deflector positioned within the housing and comprising a first set of deflectors and a second set of deflectors positioned below the first set of deflectors, wherein the second set of deflectors is positioned below the first axial aperture and the first set of deflectors is positioned above the second set of deflectors.

Abstract: A wafer having ?LEDs is inspected using cathodoluminescence microscopes. A fast scan is enabled by splitting the CL beam into several beams and sensing the beams with point detectors. Optical filters are inserted in the optical path upstream of the detectors, such that each detector senses a different frequency band. The signals are ratioed and the ratios are compared to expected reference. Regions of extreme value are identified and, if desired, a high resolution scan is performed on the regions or a sample of the regions. Viability score is calculated for each identified region.

Abstract: Method for investigating samples by time-series emission of cathodoluminescence (CL) microscope having electron beam and light sensor. In discovery scan, changes caused by the electron beam are unknown, in an inspection scan changes have already been identified in similar sample. Discovery scan starts by setting parameters of the electron beam to irradiate at a first rate of dose; flushing the buffer of the light sensor; scanning the electron beam over an area of interest on the sample while collecting CL emission with the light sensor, while preventing any reading of the data from the buffer until the entire scanning has been completed; once the entire scanning has been completed, blanking the electron beam and interrogating the buffer to identify a first CL image; and then interrogating the buffer to fetch all remaining CL images and tagging all fetched CL images according to time sequence starting from the first CL image.

Abstract: A cathodoluminescence microscope and method are used to identify and classify dislocations within a semiconductor sample. At least two CL polarized images are concurrently obtained from the sample. The images are added together to obtain a total intensity image. A normalized difference of the images is taken to obtain a degree of polarization (DOP) image. The total intensity and DOP images are compared to differentiate between edge dislocations and screw dislocations within the sample. Edge dislocation density and screw dislocation density may then be calculated.

Abstract: A scanning electron microscope having a spectrometer with a sensor having a plurality of pixels, wherein the spectrometer directs different wavelengths of collected light onto different pixels. An optical model is formed and an error function is minimized to find values for the model, such that wavelength detection may be corrected using the model. The model can correct for errors generated by effects such as the motion of the electron beam over the specimen, aberrations introduced by optical elements, and imperfections of the optical elements. A correction function may also be employed to account for effects not captured by the optical model.