OVERLAY METROLOGY KEY DEVICE OF SEMICONDUCTOR LITHOGRAPHY PROCESS AND METHOD FOR MEASURING THE SAME

摘要

PURPOSE: An overlay metrology key device is provided to achieve an accurate overlay alignment in a lithography process. CONSTITUTION: An overlay metrology key device includes a main scale(400) formed in a first element layer on a semiconductor substrate, and a sub scale(410) formed on a second element layer of a semiconductor substrate. Each cornet of the sub scale is connected as a bridge type format on each side of a bulk pattern formed on the second element layer. Thereby, the overlay metrology key device measures a degree of alignment of the second element layer in a manufacturing process of the semiconductor IC.