Device and method for detecting projection objective wave-front aberration

A device for detecting projection objective wave-front aberration, comprising:

• a light source and illuminating system (1), the light source and illuminating system (1) comprising a light source for outputting a spatial incoherent light with an illumination numerical aperture at a direction of the spatial incoherent light,
• an object plane grating (2),
• an object plane displacement stage (3),
• a measured projection objective (4),
• an image plane grating (5),
• a two-dimensional photoelectric sensor (6),
• an image plane displacement stage (7), and
• a control processing unit (8),
• wherein the object plane grating (2) is carried by the object plane displacement stage (3), and the image plane grating (5) and the two-dimensional photoelectric sensor (6) are carried by the image plane displacement stage (7);
• the object plane grating (2), the measured projection objective (4), the image plane grating (5), and the two-dimensional photoelectric sensor (6) are sequentially arranged along the direction of the spatial incoherent light output by the light source and illuminating system (1), wherein the object plane grating (2) is located in an object field of the measured projection objective (4) and uniformly illuminated by the light source and illuminating system (1), and the illumination numerical aperture of the light source and illuminating system (1) fills the object numerical aperture range of the measured projection objective (4);
• the image plane grating (5) is located in the image-side field of the measured projection objective (4), and the object plane grating (2) is imaged on the image plane grating (5);
• the two-dimensional photoelectric sensor (6) receives interference fringes generated by multi-level diffracted light of the image plane grating (5), and the receiving range comprises the image-side numerical aperture of the measured projection objective (4);
• and the control processing unit (8) is respectively connected with and controls the work of the object plane displacement stage (3), the image plane displacement stage (7) and the two-dimensional photoelectric sensor (6);
• the object plane grating (2) is a one-dimensional grating or a two-dimensional grating, and the object plane grating (2) comprises a pair of gratings with shearing diffraction directions in an X direction and a Y direction respectively;
• when the object plane grating (2) is one-dimensional, the length of grating lines of the gratings equals the period of the image plane grating (5) in the Y direction or the X direction divided by an amplification factor of the measured projection objective (4) in the Y direction or the X direction and then multiplied by a positive integer;
• when the object plane grating (2) is two-dimensional, the duty ratio thereof at the grating in a direction perpendicular to the shear direction is 1:1;
• the grating period in the direction perpendicular to the shear direction equals the period of the image plane grating (5) in the direction divided by an amplification factor of the measured projection objective (4) in the direction, and then multiplied by 2N, wherein N is a positive integer;
• or the grating period in a direction perpendicular to the shear direction equals the period of the image plane grating (5) in the direction divided by an amplification factor of the measured projection objective (4) in the direction, and then multiplied by 1/(4N′), the number of periods of the object plane grating (2) is greater than or equal to 8N′, and N′ is a positive integer.