System and Method of Correcting Errors in SEM-Measurements

A method of correcting scaling errors in scanning electron measurements, the method comprising:

• projecting a layout pattern with test structures and a plurality of assist structures onto a patterning layer by providing a mask with the layout pattern so as to create a test pattern;
• recording an image of the test pattern with a scanning electron microscope;
• extracting feature edges of the test pattern within the image;
• calculating at least one scaling error of the image during the step of recording by comparing the extracted feature edges of the assist structures with the layout pattern;
• modifying feature edges of the test structures within the test pattern by incorporating the at least one scaling error so as to at least partially compensate the scaling errors;
• and
• verifying a model for optical proximity corrections by using the modified feature edges of the test structures.

A system of correcting scaling errors in scanning electron measurements, the system comprising:

• means for projecting a layout pattern onto a patterning layer by providing a mask with the layout pattern so as to create a test pattern, the layout pattern comprising test structures and a plurality of assist structures;
• means for recording an image of the test pattern with a scanning electron microscope;
• means for extracting feature edges of the test pattern within the image;
• means for calculating at least one scaling error of the image during the step of recording by comparing extracted feature edges of the assist structures with the layout pattern;
• and
• means for modifying feature edges of the test structures within the test pattern by incorporating the at least one scaling error so as to at least partially compensate the scaling errors.

A computer readable medium, the computer readable medium including instructions capable of performing the following steps on a computer:

• extracting feature edges of a test pattern within an image;
• calculating at least one scaling error of the image by comparing extracted feature edges of assist structures with a layout pattern;
• modifying feature edges of test structures within the test pattern by incorporating the at least one scaling error so as to at least partially compensate the scaling errors;
• and
• verifying a model for optical proximity corrections by using the modified feature edges of the test structures.