Anti-Reflective Coatings: A Story of Interfaces

摘要

The semiconductor manufacturing industry has moved into an era where lithographic patterning can no longer be performed by simply coating the wafer with a layer of photoresist, exposing and developing that photoresist and then etching the desired feature onto the wafer's surface (the photoresist acts as a mask). Instead, it is necessary to deposit an extra layer - maybe two or three -before the photoresist is spun on. This extra layer is designed to prevent reflection of light that is transmitted through the photoresist, reflected off the substrate and back into the photoresist, where it can interfere with incoming light and cause the resist to be unevenly exposed.