Hermetic cap layers formed on low-k films by plasma enhanced chemical vapor deposition

A system for forming a cap layer over a dielectric layer on a substrate, the system comprising:

• a housing configured to form a processing chamber;
• a gas distribution system to flow about 200 mgm to about 8000 mgm of a silicon containing precursor, about 2000 to about 20000 sccm of oxygen (O2), and about 2000 sccm to about 20000 sccm of carrier gas through a gas distribution faceplate and into the processing chamber;
• a plasma generation system configured to form a plasma within said processing chamber, wherein said plasma generation system comprises one or more RF generators that supply about 50 watts to about 100 watts of low frequency RF power to the plasma, and about 100 watts to about 600 watts of high frequency RF power to the plasma;
• and
• a substrate holder configured to hold the substrate about 350 to about 450 mils from the gas distribution faceplate within the processing chamber, wherein the cap layer formed has a thickness of about 600 Å or less.

An integrated circuit device comprising:

• a silicon substrate;
• a low-κ dielectric layer deposited on the substrate, wherein the low-κ layer has a κ-value of about 4 or less;
• and
• a cap layer formed on the low-κ layer, wherein the cap layer has a thickness of about 600 Å or less and a compressive stress level of about 200 MPa or more.

An integrated circuit device comprising:

• a silicon substrate;
• a barrier layer formed on the silicon substrate;
• a first dielectric layer formed on the barrier layer;
• an etch stop layer formed on the first dielectric layer;
• a second dielectric layer formed on the etch stop layer;
• a cap layer formed on the second dielectric layer, wherein the cap layer has a thickness of about 600 Å or less and a compressive stress level of about 200 MPa or more;
• and
• a trench extending from the barrier layer through the cap layer, wherein the trench is filled with a conductive material to form an interconnect.