Patent ID: 10867794

Abstract:
A hard mask formed over a patterned photoresist layer in a tri-layer photoresist and a method for patterning a target layer using the same are disclosed. In an embodiment, a method includes depositing a photoresist layer over a first hard mask layer; patterning the photoresist layer to form a plurality of openings in the photoresist layer; depositing a second hard mask layer over the photoresist layer, the second hard mask layer filling the plurality of openings, the second hard mask layer having a first etch selectivity relative to the first hard mask layer, the photoresist layer having a second etch selectivity relative to the first hard mask layer, the first etch selectivity being greater than the second etch selectivity; planarizing the second hard mask layer; removing the photoresist layer; and etching the first hard mask layer using the second hard mask layer as a mask.