Methods for fabricating an interlayer dielectric layer of a semiconductor device

1. A method for fabricating an interlayer dielectric layer comprising:

forming a metallic interconnect on a substrate;

depositing an SRO layer on the metallic interconnect while the substrate is located in a chamber;

forming an FSG layer on the SRO layer without removing the substrate from the chamber

performing a purge process with an inert gas after the FSG layer is formed;

depositing a second SRO layer on the FSG layer without removing the substrate from the chamber; and

performing a planarization process on the second SRO layer, wherein the second SRO layer is planarized to a thickness that prevents the diffusion of fluorine of the FSG layer.

2. A method as defined in claim 1 , wherein the SRO layer is formed using RF power between about 2000 W and about 5000 W, between about 90 sccm and about 130 sccm of SiH 4 gas, between about 120 sccm and about 160 sccm of O 2 gas, and between about 60 sccm and about 70 sccm of Ar gas.

3. A method as defined in claim 1 , wherein the second SRO layer is formed using RF power between about 2000 W and about 5000 W, between about 90 sccm and about 130 sccm of SiH 4 gas, between about 120 sccm and about 160 sccm of O 2 gas, and between about 60 sccm and about 70 sccm of Ar gas.

4. A method as defined in claim 1 , wherein the FSG layer is formed using RF power between about 2000 W and about 5000 W, between about 60 sccm and about 110 sccm of SiH 4 gas, between about 120 sccm and about 160 sccm of O 2 gas, between about 60 sccm and about 70 sccm of Ar gas, and between about 50 sccm and about 80 sccm of SiF 4 .

5. A method as defined in claim 1 , wherein the SRO layer on the metallic interconnects has a thickness between about 500 Å and about 2000 Å.

6. A method as defined in claim 1 , wherein the SRO layer has a refractive index between about 1.5 and 1.6.

7. A method as defined in claim 1 , wherein the second SRO layer has a refractive index between about 1.5 and 1.6.