Common alignment target image field stitching method for step and repeat alignment in photoresist

摘要

A method of for aligning step and repeat reticle images for 2 adjacent sliders for magnetoresistive (MR) devices. The invention forms 3 wafer alignment targets for two adjacent sliders . The 3 wafer alignment targets are used to align adjacent reticle exposure fields. An novel common alignment target is between the two sliders. The stepper alignment system uses the wafer alignment target placed in the field stitch area between two adjacent fields and the alignment target for that particular field to align the reticle. The method includes: forming (1) a first wafer alignment target in the first slider area; (2) a second wafer alignment target in the second slider area; and (3) a center wafer alignment target between the first and the second wafer alignment targets. Using a stepper, exposing the first slider area with the reticle image field. The first reticle image field having spaced first and second reticle alignment keys. The first alignment key is aligned with the first wafer alignment target and the second reticle alignment key is aligned with the center alignment target. Next, stepping and exposing the second slider area with a second reticle image field by aligning a first reticle alignment key with the center wafer alignment target and aligning the second reticle alignment key of the second reticle image field with the second wafer alignment target.