Low temperature process to produce low-K dielectrics with low stress by plasma-enhanced chemical vapor deposition (PECVD)
Low K dielectric films exhibiting low mechanical stress may be formed utilizing various techniques in accordance with the present invention. In one embodiment, carbon-containing silicon oxide films are formed by plasma-assisted chemical vapor deposition at low temperatures (300° C. or less). In accordance with another embodiment, as-deposited carbon containing silicon oxide films incorporate a porogen whose subsequent liberation reduces film stress.
1. A method of depositing a carbon-doped silicon oxide film on a wafer, the method comprising:
mixing a silicon containing precursor with a carbon containing precursor in the presence of a plasma to deposit a carbon doped silicon oxide film having a stress of about 20 MPa or less;
wherein as deposited, the carbon-doped silicon oxide film comprises a porogen, the method further comprising:
annealing the as-deposited carbon doped silicon oxide film to liberate the porogen.
2. The method of claim 1 wherein the porogen comprises a linear organic molecule.
3. The method of claim 1 wherein the porogen comprises a cyclic organic molecule.
4. The method of claim 1 wherein the annealing comprises applying thermal energy to the as-deposited carbon doped silicon oxide film.
5. The method of claim 1 wherein the mixing occurs at a temperature of less than 300° C.
6. The method of claim 1 wherein the annealing comprises applying an electron beam cure step to the as-deposited carbon doped silicon oxide film.
7. The method of claim 6 wherein the carbon doped silicon oxide film exhibits a dielectric constant of 3.0 or less following the electron beam cure step.