Patent ID: 9401275
Filing Date: 2016-07-26
CPC Classification: H01L

Claim Text:
1. A method of forming a patterned multi-layer stack, the method comprising: depositing a first layer of a first material that is electrically conductive over a substrate, the first layer having a first stress; subsequently depositing a second layer of a second material on the first layer, the second layer being thinner than the first layer, the second layer having a second stress; subsequently depositing a third layer of a third material on the second layer, the third layer being thinner than the first layer, the third layer having a third stress that is opposite of the first stress, wherein the third stress generates a force that is substantially equal in magnitude to opposing forces generated by combined first and second stresses; subsequently forming a mask pattern over the third layer; and subsequently etching the third layer, the second layer, and the first layer with the mask pattern in place over the third layer, using anisotropic etching with a lower etching rate for the second material than the first material.