Low dielectric constant dielectric protective spacer for forming through-substrate via pattern in low dielectric constant wiring layer

摘要

A low dielectric constant dielectric protective spacer is provided for forming a through-substrate via (TSV) pattern in a low dielectric constant wiring layer. A method of forming a low dielectric constant dielectric protective spacer includes forming via openings in the low dielectric constant dielectric interconnect layer by etching. A protective layer is deposited in the via opening and on the low dielectric constant dielectric interconnect layer. At least a portion of the protective layer is etched away from the bottom of the via opening and the horizontal plane of the low dielectric constant dielectric interconnect layer. This etching leaves a protective sidewall spacer on the sidewall of the via opening. A through-substrate via is formed by etching in the bottom of the via opening and the semiconductor substrate. Fill the through-substrate via with a conductive material.