Method for forming semiconductor die

A method, comprising:

• forming a photoresist layer over a wafer;
• performing a first exposure process, through a first photomask, to a first portion and a second portion of the photoresist layer within a first area of the wafer, wherein the first photomask has an alignment mark pattern correspond to the second portion of the photoresist layer;
• performing a second exposure process, through a second photomask, to a third portion of the photoresist layer within a second area of the wafer, wherein the second portion of the photoresist layer is within a stitching zone of the wafer, the stitching zone being an overlapping region of the first area and the second area;
• and
• performing a development process to remove the first, second, and third portions of the photoresist layer to form a patterned photoresist layer.

A method, comprising:

• forming semiconductor devices within a first device region and a second device region of a substrate, and absent within a non-device region of the substrate, wherein the non-device region separates the first device region from the second device region;
• forming an alignment mark over the non-device region of the substrate, wherein a portion of the alignment mark extends into the first device region of the substrate;
• and
• forming features over the first and second device regions using the alignment mark.