Apparatus and method for determining a position of an element on a photolithographic mask

A method for determining a position of at least one element on a photolithographic mask, the method including the steps of:

• a. at least partial scanning of the at least one element on the photolithographic mask and of a first reference object by at least one particle beam of a scanning particle microscope in a common scanning process in which the first reference object is disposed on the scanning particle microscope;
• b. determining a relative position of the at least one element on the photolithographic mask relative to the first reference object from the scan data;
• and
• c. determining a distance between the first reference object and a second reference object by use of a distance measuring device, the second reference object being different from the first reference object, wherein there is a relationship between the second reference object and the photolithographic mask, and wherein the relationship comprises a known distance between the second reference object and the photolithographic mask.

A computer program containing instructions which prompt a computer system of an apparatus for determining a position of at least one element on a photolithographic mask to carry out method steps for determining the position of the at least one element on the photolithographic mask,

• wherein the apparatus comprises:
• at least one scanning particle microscope comprising a first reference object, wherein the first reference object is disposed on the scanning particle microscope while the scanning particle microscope determines a relative position of the at least one element on the photolithographic mask relative to the first reference object;
• and
• at least one distance measuring device, which is embodied to determine a distance between the first reference object and a second reference object, the second reference object being different from the first reference object, wherein there is a relationship between the second reference object and the photolithographic mask, and wherein the relationship comprises a known distance between the second reference object and the photolithographic mask;
• and
• wherein the method steps comprise:
• at least partial scanning of the at least one element on the photolithographic mask and of the first reference object by at least one particle beam of the scanning particle microscope in a common scanning process, in which the first reference object is disposed on the scanning particle microscope;
• determining the relative position of the at least one element on the photolithographic mask relative to the first reference object from the scan data;
• and
• determining the distance between the first reference object and the second reference object by use of the distance measuring device.