Semiconductor interconnect structure and manufacturing method thereof

A method for manufacturing a semiconductor interconnect structure, comprising:

• defining an air gap region over a low k dielectric layer;
• treating the air gap region of the low k dielectric layer with microwave plasma and obtaining a treated low k dielectric region;
• removing a portion of the treated low k dielectric region to form a first conductive line trench;
• metalizing the first conductive line trench to form a first conductive line;
• and
• removing the treated low k dielectric region surrounding the first conductive line to form an air gap in the air gap region.

A method for manufacturing a semiconductor interconnect structure, comprising:

• defining an air gap region and a non-air gap region over a low k dielectric layer;
• treating the air gap region of the low k dielectric layer with microwave plasma and obtaining a treated low k dielectric region;
• removing a portion of the treated low k dielectric region to form a first conductive line trench;
• metalizing the first conductive line trench to form a first conductive line;
• removing the treated low k dielectric region surrounding the first conductive line to form an air gap in the air gap region;
• and
• forming a cap layer over the air gap region thereby cover the air gap.