Diamond-like carbon films with low dielectric constant and high mechanical strength
The present invention discloses a method including: providing a substrate; and sequentially stacking layers of two or more diamond-like carbon (DLC) films over the substrate to form a composite dielectric film, the composite dielectric film having a k value of about 1.5 or lower, the composite dielectric film having a Young's modulus of elasticity of about 25 GigaPascals or higher. The present invention further discloses a structure including: a substrate; a porous diamond-like carbon (DLC) film located over the substrate; an opening located in the porous DLC film; and a conductor located in the opening.
1. A structure comprising:
a substrate;
a porous diamond-like carbon (DLC) film disposed over said substrate, said porous DLC film comprising odd layers with no pores and even layers with pores, said pores being closed pores, said pores filled with nitrogen, said nitrogen to reduce intrinsic stress in said porous DLC film wherein an odd layer is at a top of said porous DLC film and said intrinsic stress is compressive;
an opening disposed in said porous DLC film; and
a conductor disposed in said opening.
2. The structure of claim 1 wherein said porous DLC film comprises a total porosity of about 0.60-0.75.
3. The structure of claim 1 wherein said porous DLC film comprises closed pores with an equivalent diameter of about 2-6 nm.
4. The structure of claim 1 wherein said porous DLC film comprises a thickness of about 100-500 nanometers.
5. The structure of claim 1 wherein said porous DLC film comprises a k value of about 1.5 or lower.
6. The structure of claim 1 wherein said porous DLC film comprises a Young's modulus of elasticity of about 25 GigaPascals or higher.
7. The structure of claim 1 wherein said porous DLC film comprises a shear strength of about 15 GigaPascals or higher.
8. The structure of claim 1 wherein said porous DLC film comprises diamond forms of carbon.
9. The structure of claim 1 wherein said porous DLC film comprises non-diamond forms of carbon.
10. The structure of claim 1 wherein said porous DLC film comprises aromatic carbon rings and multi-membered carbon rings.
11. The structure of claim 1 wherein said DLC film comprises discontinuities, voids, and defects.