Patent ID: 11195717

Abstract:
A four-layer photoresist and method of forming the same are disclosed. In an embodiment, a method includes forming a semiconductor fin; depositing a target layer on the semiconductor fin; depositing a BARC layer on the target layer; depositing a first mask layer over the BARC layer, the first mask layer being deposited using a plasma process with an RF power of less than 50 W; depositing a second mask layer over the first mask layer using a plasma process with an RF power of less than 500 W; depositing a photoresist layer over the second mask layer; patterning the photoresist layer, the second mask layer, the first mask layer, and the BARC layer to form a first mask; and selectively removing the target layer from a first portion of the semiconductor fin using the first mask, the target layer remaining on a second portion of the semiconductor fin.