Method for selectively sealing ultra low-k porous dielectric layer using flowable dielectric film formed from vapor phase dielectric precursor
Implementations of the methods and apparatus disclosed herein relate to pore sealing of porous dielectric films using flowable dielectric material. The methods involve exposing a substrate having an exposed porous dielectric film thereon to a vapor phase dielectric precursor under conditions such that a flowable dielectric material selectively deposits in the pores of the porous dielectric material. The pores can be filled with the deposited flowable dielectric material without depositing a continuous film on any exposed metal surface.
1. A method of sealing pores in a porous dielectric layer having an external surface and pores open to the external surface, comprising:
introducing a vapor phase silicon-containing dielectric precursor and an inorganic oxidant into a process chamber, the process chamber housing a substrate maintained at a substrate temperature lower than the vaporization temperature of the silicon-containing dielectric precursor, wherein the partial pressure of the silicon-containing dielectric precursor is below the saturation pressure of the silicon-containing dielectric precursor at the substrate temperature;
condensing the vapor phase silicon-containing dielectric precursor in the pores of the porous dielectric layer;
reacting the condensed silicon-containing dielectric precursor with the inorganic oxidant to deposit a flowable silicon-containing dielectric film by capillary condensation in the pores of the porous dielectric layer without forming a continuous silicon-containing film on the external surface of the porous dielectric layer.
2. The method of claim 1 , wherein the porous dielectric layer includes a recessed region formed therein, such that the external surface includes a surface of the recessed region, wherein pores recessed from the recess region surface are sealed by the deposited flowable silicon-containing dielectric film.
3. The method of claim 2 , wherein the deposition of the flowable silicon-containing dielectric film is performed without substantial deposition in the recessed region.
4. The method of claim 2 , further comprising forming a metal-containing layer on the recessed region surface.
5. The method of claim 4 , wherein the metal-containing layer is a manganese silicon oxide.
6. The method of claim 2 , further comprising filling the recessed region with a metal.
7. The method of claim 2 , wherein the recessed region includes an exposed metal surface, an exposed metal nitride surface, or an exposed metal oxide surface.
8. The method of claim 7 , wherein deposition of the flowable silicon-containing dielectric film is performed without deposition on the metal, metal nitride or metal oxide surface.
9. The method of claim 1 , further comprising performing a post-deposition treatment of the flowable silicon-containing dielectric film.
10. The method of claim 1 , wherein the flowable silicon-containing dielectric film is a doped or undoped silicon oxide, carbon-doped silicon oxide, silicon oxynitride, or silicon nitride material.
11. The method of claim 1 , wherein the substrate temperature is between about −20° C. and 100° C.
12. The method of claim 1 , further comprising exposing the porous dielectric layer to the silicon-containing dielectric precursor to thereby replace bonds in the porous dielectric layer.
13. The method of claim 1 , wherein the silicon-containing dielectric precursor is an alkoxysilane.
14. The method of claim 1 , wherein the silicon-containing dielectric precursor is an alkylsilane.
15. The method of claim 1 , wherein the silicon-containing dielectric precursor is an aminosilane.
16. The method of claim 1 , further comprising introducing a non-halogenated catalyst into the process chamber.
17. The method of claim 1 , wherein the flowable silicon-containing dielectric film is a carbon-doped flowable dielectric film.
18. The method of claim 1 , further comprising performing a plasma treatment after selective deposition in the pores and prior to metal cap deposition.
19. A method comprising:
providing a porous interlayer dielectric (ILD) layer having a trench, via or other recessed region formed therein exposing a metal surface;
introducing exposing the porous ILD layer to a vapor phase silicon-containing dielectric precursor in a hydrolyzing medium below the saturation pressure of the vapor phase silicon-containing dielectric precursor;
selectively condensing the silicon-containing dielectric precursor in at least the openings of the pores of the porous ILD layer and hydrolyzing the condensed silicon-containing dielectric precursor without forming a dielectric film on the metal surface;
forming a metal-containing barrier layer in the trench; and
filling the trench with a conductive material.