Metal plate corner structure on metal insulator metal

Abstract

A metal-insulator-metal (MIM) structure and methods of forming the same for reducing the accumulation of external stress at the corners of the conductor layers are disclosed herein. An exemplary device includes a substrate that includes an active semiconductor device. A stack of dielectric layers is disposed over the substrate. A lower contact is disposed over the stack of dielectric layers. A passivation layer is disposed over the lower contact. A MIM structure is disposed over the passivation layer, the MIM structure including a first conductor layer, a second conductor layer disposed over the first conductor layer, and a third conductor layer disposed over the second conductor layer. A first insulator layer is disposed between the first conductor layer and the second conductor layer. A second insulator layer is disposed between the second conductor layer and the third conductor layer. One or more corners of the third conductor layer are rounded.