LITHOGRAPHY PROCESS

摘要

A method for being used in a lithography process is provided. The method includes receiving a first mask, a second mask and a substrate with a set of baseline registration marks. A first set of registration marks is formed on the substrate using the first mask and a first exposure tool, and a first set of overlay errors is determined. The first set of registration marks is removed and a second set of registration marks is formed on the substrate using the second mask and a second exposure tool. A second set of overlay errors is determined. A set of tool-induced overlay errors is generated from the first and second sets of overlay errors and used in fabricating a third mask. The third mask can then be used in the lithography process to accommodate the overlay errors caused by different exposure tools, different masks, and different mask writers.

主权项

1. A method comprising:
providing a substrate having a set of baseline registration marks; forming a first set of registration marks on the substrate; determining a first set of overlay errors of the first set of registration marks with respect to the set of baseline registration marks; forming a second set of registration marks on the substrate; determining a second set of overlay errors of the second set of registration marks with respect to the set of baseline registration marks; generating a set of tool-induced overlay errors from the first set of overlay errors and the second set of overlay errors; and fabricating a device by using a third mask based on the set of tool-induced overlay errors.