Flat Panel Array with the Alignment Marks in Active Area

Test structures and alignment marks enable accurate measurements of alignment in the active area of an image sensor device. The alignment marks are formed in the active area replacing pixels near the lithographic shot boundaries of the array. Misalignment across the lithographic shots is assessed through the degree of shifting between the alignment patterns. The alignment marks are located in a pixel location of the active area and can measure the actual lithographic shot-to-shot misalignment in the active area, which can be used to make an accurate lithographic alignment. Having such alignment marks allows for a more accurate assessment of the in-line process manufacturing capability as well as a more rapid feedback of in-array drift, which would allow a faster and better control for yield loss.