Method and apparatus for adaptive alignment

An electron beam inspection apparatus, comprising:

• a controller having circuitry to cause the electron beam inspection apparatus to perform:
• searching for a targeted reference position in a database;
• and
• in response to a determination that the targeted reference position does not exist in the database:
• defining a current lock position and an area enclosing the current lock position on the wafer image;
• computing an alignment score of the current lock position;
• comparing the alignment score of the current lock position with stored alignment scores of positions previously selected in relation to aligning the wafer image with the reference image;
• and
• aligning the wafer image with a reference image based on the comparing.

A non-transitory computer readable medium storing a set of instructions that is executable by a controller of a device to cause the device to perform a method comprising:

• searching for a targeted reference position in a database;
• and
• in response to a determination that the targeted reference position does not exist in the database:
• defining a current lock position and an area enclosing the current lock position on the wafer image;
• computing an alignment score of the current lock position;
• comparing the alignment score of the current lock position with stored alignment scores of positions previously selected in relation to aligning the wafer image with a reference image;
• and
• aligning the wafer image with the reference image based on the comparing.