FLOWABLE DIELECTRIC FOR SELECTIVE ULTRA LOW-K PORE SEALING

• US 20160056071A1
• Filed: 08/20/2014
• Published: 02/25/2016
• Est. Priority Date: 08/20/2014
• Status: Active Grant

• Current Assignee: Lam Research Corporation, Novellus Systems Incorporated (Lam Research Corporation)
• Original Assignee: Lam Research Corporation
• Inventors: Draeger, Nerissa Sue, Ashtiani, Kaihan Abidi, Padhi, Deenesh, Wong, Derek B., van Schravendijk, Bart J., Antonelli, George Andrew, Kolics, Artur, Zhao, Lie, van Cleemput, Patrick A.
• Granted Patent: US 10,049,921 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: C23C 16/045 Coating cavities or hollow spaces, e.g. interior of tubes; Infiltration of porous substrates
• CPC Class Codes: C23C 16/401 containing silicon
• CPC Class Codes: C23C 16/56 After-treatment
• CPC Class Codes: H01L 21/3105 After-treatment
• CPC Class Codes: H01L 21/76814 post-treatment or after-treatment, e.g. cleaning or removal of oxides on underlying conductors
• CPC Class Codes: H01L 21/76825 by exposing the layer to particle radiation, e.g. ion implantation, irradiation with UV light or electrons etc. plasma treatment H01L21/76826
• CPC Class Codes: H01L 21/76826 by contacting the layer with gases, liquids or plasmas
• CPC Class Codes: H01L 21/76831 in via holes or trenches, e.g. non-conductive sidewall liners
• CPC Class Codes: H01L 21/76843 formed in openings in a dielectric
• CPC Class Codes: H01L 21/76876 for deposition from the gas phase, e.g. CVD
• CPC Class Codes: H01L 23/53238 Additional layers associated with copper layers, e.g. adhesion, barrier, cladding layers
• CPC Class Codes: H01L 23/5329 Insulating materials

Abstract

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.

Claims

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 dielectric precursor into a process chamber wherein the partial pressure of the dielectric precursor is below the saturation pressure of the dielectric precursor to thereby selectively deposit a flowable dielectric film in at least the opening of the pores 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 dielectric film.

3. The method of claim 2, wherein the deposition of the flowable dielectric film is performed without substantial deposition in the recessed region.

4. The method of claim 1, further comprising introducing an oxidant into the process chamber.

5. The method of claim 1, wherein the flowable dielectric film is deposited by capillary condensation in the pores.

6. The method of claim 1, further comprising performing a post-deposition treatment of the flowable dielectric film.

7. The method of claim 1, wherein the flowable dielectric film is a doped or undoped silicon oxide, carbon-doped silicon oxide, silicon oxynitride, or silicon nitride material.

8. The method of claim 2, further comprising forming a metal-containing layer on the recessed region surface.

9. The method of claim 8, wherein the metal-containing layer is a manganese silicon oxide.

10. The method of claim 2, further comprising filling the recessed region with a metal.

11. The method of claim 1, wherein the temperature in the process chamber is between about −

20°

C. and 100°

C.

12. The method of claim 2, wherein the bottom of the recessed region includes an exposed metal, metal nitride or metal oxide surface.

13. The method of claim 12, wherein deposition of the flowable dielectric film is performed without deposition on the metal, metal nitride or metal oxide surface.

14. The method of claim 1, further comprising exposing the porous dielectric layer to the dielectric precursor to thereby replace bonds in the porous dielectric layer.

15. The method of claim 1, wherein the dielectric precursor is an alkoxysilane.

16. The method of claim 1, wherein the dielectric precursor is an alkylsilane.

17. The method of claim 1, wherein the dielectric precursor is an aminosilane.

18. The method of claim 1, further comprising introducing a non-halogenated catalyst into the process chamber.

19. The method of claim 1, wherein the flowable dielectric film is a carbon-doped flowable dielectric film.

20. The method of claim 1, further comprising performing a plasma treatment after selective deposition in the pores and prior to metal cap deposition.

21. 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 a vapor phase dielectric precursor below the saturation pressure of the vapor phase dielectric precursor to selectively condense the dielectric precursor in at least the opening of the pores of the porous ILD layer;

forming a metal-containing barrier layer in the trench; and

filling the trench with a conductive material.

22. An apparatus comprising:

a flowable dielectric deposition chamber configured to deposit flowable dielectric film on a workpiece provided therein; and

a controller, said controller comprising instructions for;

maintaining a workpiece temperature of between −

20°

C. and 100°

C.;

introducing a dielectric precursor and a co-reactant into the deposition chamber for a time period of 5 seconds or less to thereby selectively deposit a flowable dielectric film in pores of the workpiece.