Abstract: A charged particle beam system includes a chamber having an opening in a ceiling, a table placed immediately below the opening and movable in one direction, a laser interferometer set in the chamber, including a laser oscillator placed along the moving direction of the table, a movable mirror placed on the table side opposing the oscillator, a beam splitter placed to cross the laser beam and a fixed mirror fixed, immediately above the beam splitter, on the ceiling of the chamber, an optical lens barrel having an opening communicating with the opening of the chamber, and a beam gun set on a ceiling of the optical lens barrel to irradiate a specimen placed on the table with a charged particle beam through the first and second openings. At least an upper wall portion from the opening to the fixed mirror of the chamber is made of an invar alloy.

Abstract: A charged particle beam system includes a chamber having an opening in a ceiling, a table placed immediately below the opening and movable in one direction, a laser interferometer set in the chamber, including a laser oscillator placed along the moving direction of the table, a movable mirror placed on the table side opposing the oscillator, a beam splitter placed to cross the laser beam and a fixed mirror fixed, immediately above the beam splitter, on the ceiling of the chamber, an optical lens barrel having an opening communicating with the opening of the chamber, and a beam gun set on a ceiling of the optical lens barrel to irradiate a specimen placed on the table with a charged particle beam through the first and second openings. At least an upper wall portion from the opening to the fixed mirror of the chamber is made of an invar alloy.

Abstract: The present invention provides a pattern evaluating device including light irradiating means for irradiating the rays of light from a light source upon an object, an objective lens through which the light having penetrated through the object passes, an aperture member stopping the diameter of a light beam which has passed the objective lens, a photo receiving element receiving the light beam which has had the diameter stopped by the aperture member, and judging means for evaluating the pattern, following the information of the light received by the photo receiving element and which corresponds to the pattern, wherein the aperture member is capable of changing the numerical aperture, depending whether or not the sample is provided with a pericle.