Metrology apparatus and method based on diffraction using oblique illumination and method of manufacturing semiconductor device using the metrology method

An apparatus comprising:

• a light source configured to output a light beam;
• a stage on which an object is placed;
• a reflective optical element configured to irradiate the light beam onto the object through reflection, such that the light beam is incident on the object at an inclination angle, the inclination angle being an acute angle;
• an angle adjuster configured to adjust the inclination angle;
• a detector configured to detect a diffracted light beam based on the light beam reflected and diffracted by the object, wherein a pupil image, which is an image formed on a pupil plane of the diffracted light beam, is detected;
• and
• a processor configured to measure a 3D pupil matrix for the diffracted light beam, which comprises a wavelength of the light beam, the inclination angle, and intensity of the diffracted light beam as variables, and analyze an overlay error of the object based on the 3D pupil matrix,
• wherein the reflective optical element comprises a magnification reflection type object lens, the magnification reflection type object lens comprising a first aspherical mirror having an opening at a center and a second aspherical mirror provided below the first aspherical mirror,
• wherein the light beam passes through the opening of the first aspherical mirror from a first side of the first aspherical mirror, is reflected by the second aspherical mirror, is incident on a second side of the first aspherical mirror different from the first side of the first aspherical mirror, is reflected by the first aspherical mirror, and is incident on the object at the inclination angle, and
• wherein the angle adjuster is further configured to adjust the inclination angle to expand a wavelength range of the light beam by changing a focusing position of the light beam on a pupil plane between the first aspherical mirror and the second aspherical mirror, such that sensitivity is maximized for a wavelength used the measurement of the 3D pupil matrix.

An apparatus comprising:

• a memory storing one or more instructions;
• and
• a processor configured to:
• control a light source to output a light beam, the light beam being irradiated onto the object at an inclination angle through a reflective optical element comprising a magnification reflection type object lens, the magnification reflection type object lens comprising a first aspherical mirror having an opening at a center and a second aspherical mirror provided below the first aspherical mirror;
• receive detected information corresponding to a diffracted light beam that is based on the light beam reflected and diffracted by an object;
• measure a 3D pupil matrix for the diffracted light beam based on the detected information;
• and
• analyze the object based on the 3D pupil matrix,
• wherein the light beam passes through the opening of the first aspherical mirror from a first side of the first aspherical mirror, is reflected by the second aspherical mirror, is incident on a second side of the first aspherical mirror different from the first side of the first aspherical mirror, is reflected by the first aspherical mirror, and is incident on the object at the inclination angle, and
• wherein the angle adjuster is further configured to adjust the inclination angle to expand a wavelength range of the light beam by changing a focusing position of the light beam on a pupil plane between the first aspherical mirror and the second aspherical mirror, such that sensitivity is maximized for a wavelength used the measurement of the 3D pupil matrix.