Access to eBooks is limited to institutions that have purchased
or currently subscribe to the SPIE eBooks program. eBooks are not
available via an individual subscription. SPIE books (print and
digital) may be purchased individually on
Contact your librarian to recommend SPIE eBooks for your organization.
Chapter 5: Photomask Fabrication Procedures and Limitations
This chapter is concerned with masks for optical lithography. Photomasks used in present-day semiconductor manufacturing are reduction reticles, where the pattern is formed in a chromium layer over a fused silica substrate. The pattern represents one level of an integrated circuit (IC) design. An optical stepper forms a four to five demagnified image of the reticle on the wafer. The reticle usually contains one or more identical circuit patterns plus wafer process test patterns and marks for aligning the reticle in the optical stepper. Typically, 20 to 25 different mask levels are required for a complete IC device.
Online access to SPIE eBooks is limited to subscribing institutions.