US Patent 11004685 Multi-layer structures and methods of forming

A method includes depositing a plurality of layers on a substrate, patterning a first mask overlying the plurality of layers, and performing a first etching process on the plurality of layers using the first mask. The method also includes forming a polymer material along sidewalls of the first mask and sidewalls of the plurality of layers, and removing the polymer material. The method also includes performing a second etching process on the plurality of layers using the remaining first mask, where after the second etching process terminates a combined sidewall profile of the plurality of layers comprises a first portion and a second portion, and a first angle of the first portion and a second angle of the second portion are different to each other.