Dual damascene dual alignment interconnect scheme

摘要

A stack of a first metal line and a first dielectric cap material portion is formed within a line trench of first dielectric material layer. A second dielectric material layer is formed thereafter. A line trench extending between the top surface and the bottom surface of the second dielectric material layer is patterned. A photoresist layer is applied over the second dielectric material layer and patterned with a via pattern. An underlying portion of the first dielectric cap material is removed by an etch selective to the dielectric materials of the first and second dielectric material layer to form a via cavity that is laterally confined along the widthwise direction of the line trench and along the widthwise direction of the first metal line. A dual damascene line and via structure is formed, which includes a via structure that is laterally confined along two independent horizontal directions.

主权项

1. A method of forming a metal interconnect structure comprising:
forming a first line trench extending through a first dielectric material layer on a substrate; forming a stack, from bottom to top, of a first metal line and a dielectric cap material portion within said first line trench, said dielectric cap material portion having a top surface coplanar with a top surface of said first dielectric material layer; forming a second dielectric material layer over said first dielectric material layer and said stack; forming a second line trench extending through said second dielectric material layer; forming a via cavity extending to a top surface of said first metal line underneath said second line trench by removing a portion of said dielectric cap material portion, wherein said via cavity is laterally surrounded by said first dielectric material layer; and forming a dual damascene line and via structure including a second metal line located within said second line trench and a via structure located within said via cavity.