US Patent 10163691 Low-K dielectric interconnect systems

A method of fabricating a semiconductor device includes forming a low-k dielectric layer over a substrate and depositing a cap layer over the low-k dielectric layer. A treatment process is performed to the cap layer. After the treatment process to the cap layer is performed, the low-k dielectric layer is etched to form a plurality of trenches using the cap layer as an etching mask.