Dummy patterns and method of manufacture for mechanical strength of low k dielectric materials in copper interconnect structures for semiconductor devices

Abstract

A method for fabricating a semiconductor device. The method includes providing a semiconductor substrate including a surface region. The method forms a first interlayer dielectric overlying the surface region and forms an interconnect layer overlying the first interlayer dielectric layer. The method also forms a low K dielectric layer overlying the interconnect layer, which has a predetermined shape. The method forms a copper interconnect layer overlying the low K dielectric layer. In a preferred embodiment, the low K dielectric layer maintains the predetermined shape using a dummy pattern structure provided within a portion of the low K dielectric layer to mechanically support and maintain the predetermined shape of the low K dielectric layer between the interconnect layer and the copper interconnect layer.