Patent Number: 
Section: claims

1. A method for evaluating optical performance of an inspection apparatus that uses a charged particle beam, the method comprising:providing the inspection apparatus with a charged-particle-beam (CPB) mapping optical system and an electron emitter that emits an electron beam spontaneously;providing, on a surface of the electron emitter, an evaluation chart having a pattern over the surface;using the CPB mapping optical system, producing an image of the evaluation chart; andbased on an observation of the image of the evaluation chart, determining a resolution of the CPB mapping optical system. 2. A method for evaluating optical performance of an inspection apparatus that uses a charged particle beam, the method comprising:providing the inspection apparatus with a charged-particle-beam (CPB) mapping optical system and an electron emitter that emits an electron beam spontaneously;providing, on a surface of the electron emitter, an evaluation chart having a dot pattern over the surface;using the CPB mapping optical system, producing an image of the evaluation chart; andbased on an observation of the image of the evaluation chart, adjusting an optical axis of the mapping optical system. 3. A method for evaluating optical performance of an inspection apparatus that uses a charged particle beam, the method comprising:providing the inspection apparatus with a charged-particle-beam (CPB) optical system and an electron emitter that emits an electron beam spontaneously;providing, on a surface of the electron emitter, an evaluation chart having a dot pattern over the surface;using the CPB optical system, observing the evaluation chart; andbased on the observation of the evaluation chart, adjusting an optical axis of the CPB optical system. 4. A method for evaluating optical performance of an inspection apparatus that uses a charged particle beam, the method comprising:providing the inspection apparatus with a charged-particle-beam (CPB) mapping optical system and an electron emitter that emits an electron beam spontaneously;providing, on a surface of the electron emitter, an evaluation chart having a cross pattern or an L-shaped pattern over the surface;using the CPB mapping optical system, producing an image of the evaluation chart; andbased on an observation of the image of the evaluation chart, adjusting an aberration of the CPB mapping optical system.