Air gap forming techniques based on anodic alumina for interconnect structures

摘要

An aluminum (Al) layer is formed over a semiconductor substrate. A selective portion of the Al layer is removed to form openings. The Al layer is anodized to obtain an alumina dielectric layer with a plurality of pores. The openings are filled with a conductive interconnect material. The pores are widened to form air gaps and a top etch stop layer is formed over the alumina dielectric layer.

主权项

1. A semiconductor device comprising:
a first conductive layer disposed over a semiconductor substrate; a second conductive layer disposed over the first conductive layer; an alumina dielectric layer arranged between the first and second conductive layers to provide electrical isolation between the first and second conductive layers, the alumina dielectric layer including an alumina matrix with a plurality of air gaps extending through the alumina matrix; and a copper body extending through the alumina dielectric layer to electrically couple the first conductive layer to the second conductive layer.