METHOD AND STRUCTURE FOR IMPROVED ALIGNMENT IN MRAM INTEGRATION

摘要

A method for aligning a semiconductor device structure is provided to align efficiently even a first mark set by forming first and second align mark sets in the same mask level. A first align mark set(106a) is formed in the lower level of a semiconductor device structure, and a second align mark set(106b) is formed near the first align mark set. An opaque layer is formed on the lower level of the semiconductor device structure including first and second align mark sets. A part of the opaque layer corresponding to the position of the first align mark set is opened so that the first align mark set is optically monitored and the second align mark set is left as the second align mark is initially covered with the opaque layer. The opaque layer is lithographically patterned by using the optically monitored first align mark set. The first and the second align mark sets can include both align marks(102) and overlay boxes(104).