Patent ID: 11899358
Assignee: CARL ZEISS SMT GMBH
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 15:
16. A method of generating structures on a wafer using a double exposure by a first photomask and a second photomask, the method comprising:
recording an aerial image of at least one region of the first photomask to generate a recorded aerial image of the at least one region of the first photomask;
defining at least one region of interest of the first photomask;
ascertaining structure edges in the at least one region of interest of the first photomask based on the recorded aerial image to generate ascertained structure edges of the first photomask;
providing desired structures to be produced by the first photomask;
adapting the ascertained structure edges in the at least one region of interest of the first photomask to the desired structures to be produced by the first photomask to generate adapted structure edges of the first photomask, wherein the ascertained structure edges of the first photomask are fitted to the desired structures to be produced by the first photomask;
displacing the adapted structure edges of the first photomask by use of the results of a separate registration measurement of the first photomask;
recording a second aerial image of at least one region of a second photomask;
defining at least one region of interest of the second photomask;
ascertaining structure edges in the at least one region of interest of the second photomask to generate ascertained structure edges of the second photomask;
providing desired structures to be produced by the second photomask;
adapting the ascertained structure edges of the second photomask to the desired structures to be produced by the second photomask to generate adapted structure edges of the second photomask, wherein the ascertained structure edges of the second photomask are fitted to the desired structures to be produced by the second photomask; and
displacing the adapted structure edges of the second photomask by use of the results of a separate registration measurement of the second photomask.