Inspection of a semiconductor specimen

A computerized method of inspecting a semiconductor specimen, the method comprising:

• acquiring, by an inspection machine, a first image of an inspection area of a die of the semiconductor specimen and a group of reference images corresponding to a group of candidate reference units proximate to the inspection area and selectable to be used for inspecting the inspection area, the inspection area comprising at least one inspection unit or part thereof, each inspection unit comprising one or more regions repetitive with respect to corresponding regions of one or more reference units proximate to the inspection unit, the one or more reference units having the same size and design pattern as of the inspection unit and usable for inspection of the inspection unit;
• obtaining, by a processing and memory circuitry (PMC), a second image informative of one or more partitions of the inspection area respectively associated with one or more inspection algorithms, wherein the second image is aligned with the first image, and the one or more inspection algorithms are usable to inspect pixels of the first image aligned within the one or more partitions;
• for each given pixel of the first image, by the PMC, determining location of one or more reference pixels thereof based on an inspection algorithm associated with a respective partition of the second image that the given pixel is aligned within;
• selecting, by the PMC, from the group of candidate reference units, one or more specific reference units actually required for inspecting the inspection area, based on the determined location of reference pixels for at least some pixels of the first image;
• and
• using by the PMC, one or more reference images corresponding to the selected reference units to inspect the first image, thereby providing an inspection result of the inspection area.

A non-transitory computer readable storage medium tangibly embodying a program of instructions that, when executed by a computer, cause the computer to perform a method of inspecting a semiconductor specimen, the method comprising:

• obtaining, acquiring by an inspection machine, a first image of an inspection area of a die of the semiconductor specimen and a group of reference images corresponding to a group of candidate reference units proximate to the inspection area and selectable to be used for inspecting the inspection area, the inspection area comprising at least one inspection unit or part thereof, each inspection unit comprising one or more regions repetitive with respect to corresponding regions of one or more reference units proximate to the inspection unit, the one or more reference units having the same size and design pattern as of the inspection unit and usable for inspection of the inspection unit;
• obtaining, by a processing and memory circuitry (PMC), a second image informative of one or more partitions of the inspection area respectively associated with one or more inspection algorithms, wherein the second image is aligned with the first image, and the one or more inspection algorithms are usable to inspect pixels of the first image aligned within the one or more partitions;
• for each given pixel of the first image, determining, by the PMC, location of one or more reference pixels thereof based on an inspection algorithm associated with a respective partition of the second image that the given pixel is aligned within;
• selecting, by the PMC, from the group of candidate reference units, one or more specific reference units actually required for inspecting the inspection area, based on the determined location of reference pixels for at least some pixels of the first image;
• and
• using, by the PMC, one or more reference images corresponding to the selected reference units to inspect the first image, thereby providing an inspection result of the inspection area.