Dielectric layers for semiconductor devices and methods of forming the same

Abstract

Methods of forming improved dielectric layers and semiconductor devices formed by the same are disclosed. In an embodiment, a semiconductor device includes a transistor structure on a semiconductor substrate; a first dielectric layer on the transistor structure; a second dielectric layer on the first dielectric layer, the second dielectric layer having a nitrogen concentration greater than a nitrogen concentration of the first dielectric layer; a first conductive structure extending through the second dielectric layer and the first dielectric layer, the first conductive structure being electrically coupled to a first source/drain region of the transistor structure, a top surface of the first conductive structure being level with a top surface of the second dielectric layer; and a second conductive structure physically and electrically coupled to the first conductive structure, a bottom surface of the second conductive structure being a first distance below the top surface of the second dielectric layer.