Electron beam apparatus with detailed observation function and sample inspecting and observing method using electron beam apparatus
View Patent ↗Provided is a sample observing method allowing for a detailed observation of a sample by using one and the same electron beam apparatus. The method uses an electron beam apparatus 1 comprising a primary optical system 10 serving for irradiating the electron beam onto the sample surface and a secondary optical system 30 serving for detecting secondary electrons emanating from said sample surface to form an image of the sample surface. The inspection is carried out on the sample surface, S, by irradiating the electron beam to the sample surface, and after the extraction of a defective region in the sample based on the inspection, the extracted defective region is once again applied with the irradiation of the electron beam so as to provide a magnification or a detailed observation of the defective region.
1. A sample observing method for performing observation of a sample surface using an electron beam irradiation, comprising the steps of:
irradiating an electron beam formed in a first shape in section view to a sample surface and detecting electrons consequently emanating from said sample surface to thereby provide inspection of said sample surface;
extracting a defective region in the sample based on the inspection; and
irradiating the electron beam formed in a second shape in section view to said extracted defective region to thereby provide magnification or detailed observation of said defective region, wherein an illumination area of said sample surface by electron beam in said second shape is smaller than an illumination area when the electron beam in said first shape emanates from said sample surface.
2. A sample observing method according to claim 1 , in which an electron beam apparatus for performing said inspection of the sample surface is an apparatus having an optical system of image projection type and capable of performing both of said inspection of the sample surface and said detailed observation.
3. A sample observing method according to claim 1 , in which a large-magnification observation mode of image projection type is employed in said detailed observation.
4. A sample observing method according to claim 1 , in which an optical system of image projection type is used in said inspection of the sample surface and an optical system of scanning electron microscope type having a secondary electron detector positioned in the vicinity of the sample is used in said detailed observation.
5. A sample observing method according to claim 1 , in which a line sensor is for performing said inspection of the sample surface, wherein said inspection of the sample surface and said detailed observation are simultaneously performed, while the sample or a wafer stage is continuously moving.
6. A sample observing method according to claim 1 , in which a control electrode is arranged between an objective lens and the sample in a primary optical system of said electron beam apparatus for performing said inspection of the sample surface, wherein said control electrode is applied with a potential in a range of 0 V to 10 kV relative to a wafer potential so as to intensify an electric field between the sample and said control electrode and thus improve secondary electron collection efficiency and/or reduce distortion for performing said inspection of said sample surface and said detailed observation.
7. A sample observing method according to claim 1 , in which a control electrode is arranged between an objective lens and the sample in a primary optical system of said electron beam apparatus for performing said inspection of the sample surface, wherein said control electrode is applied with a potential in a range of 1 V to −1 kV relative to a wafer potential so as to decrease a potential difference between the sample and said control electrode and thus increase an optical magnification and/or suppress discharge for performing said inspection of the sample surface and said detailed observation.