Patent ID: 11392036

Abstract:
Multi-layer photoresists, methods of forming the same, and methods of patterning a target layer using the same are disclosed. In an embodiment, a method includes depositing a reflective film stack over a target layer, the reflective film stack including alternating layers of a first material and a second material, the first material having a higher refractive index than the second material; depositing a photosensitive layer over the reflective film stack; patterning the photosensitive layer to form a first opening exposing the reflective film stack, patterning the photosensitive layer including exposing the photosensitive layer to a patterned energy source, the reflective film stack reflecting at least a portion of the patterned energy source to a backside of the photosensitive layer; patterning the reflective film stack through the first opening to form a second opening exposing the target layer; and patterning the target layer through the second opening.