FABRICATION OF POROGEN RESIDUES FREE AND MECHANICALLY ROBUST LOW-K MATERIALS

• US 20110006406A1
• Filed: 07/07/2010
• Published: 01/13/2011
• Est. Priority Date: 07/08/2009
• Status: Abandoned Application

• Current Assignee: IMEC International, Katholieke Universiteit Leuven
• Original Assignee: IMEC International, Katholieke Universiteit Leuven
• Inventors: Vanstreels, Kris, De Gendt, Stefan, Shamiryan, Denis, Verdonck, Patrick, Baklanov, Mikhail, Urbanowicz, Adam Michal
• Application Number:
  US12/831,935
• Publication Number:
  US 20110006406A1
• Time in Patent Office: Days
• US Class Current: 257/632
• CPC Class Codes: C23C 16/401 containing silicon
• CPC Class Codes: C23C 16/56 After-treatment
• CPC Class Codes: H01L 21/02126 the material containing Si, O, and at least one of H, N, C, F, or other non-metal elements, e.g. SiOC, SiOC:H or SiONC
• CPC Class Codes: H01L 21/02203 the layer being porous
• CPC Class Codes: H01L 21/02271 deposition by decomposition or reaction of gaseous or vapour phase compounds, i.e. chemical vapour deposition H01L21/02266 takes precedence
• CPC Class Codes: H01L 21/0234 treatment by exposure to a plasma
• CPC Class Codes: H01L 21/02348 treatment by exposure to UV light
• CPC Class Codes: H01L 21/3105 After-treatment
• CPC Class Codes: H01L 21/31633 Deposition of carbon doped silicon oxide, e.g. SiOC
• CPC Class Codes: H01L 21/7682 the dielectric comprising air gaps
• CPC Class Codes: H01L 2221/1047 the air gaps being formed by pores in the dielectric

Abstract

A method is provided for producing a porogen-residue-free ultra low-k film with porosity higher than 50% and a high elastic modulus above 5 GPa. The method starts with depositing a SiCOH film using Plasma Enhanced Chemical Vapor Deposition (PE-CVD) or Chemical Vapor Deposition (CVD) onto a substrate and then first Performing an atomic hydrogen treatment at elevated wafer temperature in the range of 200° C. up to 350° C. to remove all the porogens and then performing a UV assisted thermal curing step.

Claims

1. A method for producing a porogen-residue-free ultra low-k film, comprising:

depositing an organo-silica matrix comprising an organic porogen on a substrate by at least one technique selected from the group consisting of plasma enhanced chemical vapor deposition, chemical vapor deposition, and spin-on deposition;

thereafter

performing a porogen removal step; and

thereafter

performing a curing step, whereby a porogen-residue-free ultra low-k film is obtained.

2. The method of claim 1, wherein depositing an organo-silica matrix and performing a porogen removal step are repeated one or more times, and wherein performing a curing step is repeated one or more times.

3. The method of claim 1, wherein the porogen-residue-free ultra low-k film has a k-value of from 1.8 to 2.6, a porosity higher than 48% and an elastic modulus above 3 GPa.

4. The method of claim 1, wherein the porogen-residue-free ultra low-k film has a k-value of greater than 2.0, with a porosity higher than 48% and an elastic modulus above 5 GPa.

5. The method of claim 1, wherein the substrate is silicon.

6. The method of claim 1, wherein the organo-silica matrix comprises a cyclic aromatic hydrocarbon.

7. The method of claim 1, wherein the organo-silica matrix comprises a SiCOH film.

8. The method of claim 1, wherein performing a porogen removal step comprises atomic hydrogen treatment at a wafer temperature of from 200°

C. to 350°

C. for from 10 seconds to 800 seconds.

9. The method of claim 1, wherein performing a porogen removal step comprises atomic hydrogen treatment at a wafer temperature of from 200°

C. to 350°

C. for from 10 seconds to 400 seconds.

10. The method of claim 1, wherein performing a curing step comprises performing a UV assisted thermal curing step at a wavelength of less than 200 nm.

11. The method of claim 1, wherein performing a curing step comprises performing a UV assisted thermal curing step at a wavelength of 172 nm.

12. The method of claim 7, wherein the SiCOH film is a plasma enhanced chemical vapor deposition or chemical vapor deposition deposited SiCOH film with a film thickness of from 20 nm to 190 nm.

13. The method of claim 7, wherein the SiCOH film is a plasma enhanced chemical vapor deposition or chemical vapor deposition deposited SiCOH film with a film thickness of from 40 nm to 140 nm.

14. The method of claim 7, wherein the SiCOH film is a plasma enhanced chemical vapor deposition or chemical vapor deposition deposited SiCOH film comprising multiple layers, each layer having a film thickness of from 20 nm to 190 nm.

15. The method of claim 8, wherein atomic hydrogen treatment is performed in an afterglow of a hydrogen comprising plasma, whereby a presence of hydrogen excited radicals, ions, electrons, and UV light is avoided.

16. The method of claim 8, wherein atomic hydrogen treatment is performed in an afterglow of a hydrogen comprising plasma, wherein the hydrogen comprising plasma further comprises at least one enhancer.

17. The method of claim 8, wherein atomic hydrogen treatment is performed in an afterglow of a hydrogen comprising plasma, and wherein the hydrogen comprising plasma is operated at a microwave power of from 100 W to 2500 W.

18. The method of claim 8, wherein atomic hydrogen treatment is performed in an afterglow of a hydrogen comprising plasma, and wherein the hydrogen comprising plasma is operated at a gas pressure of from 13.3 Pa to 300 Pa.

19. The method of claim 8, wherein atomic hydrogen treatment is performed in an afterglow of a hydrogen comprising plasma, and wherein the hydrogen comprising plasma is operated at a microwave power of 2500 W, a gas pressure of 100 Pa, and a hydrogen gas flow of 950 sccm hydrogen.

20. The method of claim 8, wherein atomic hydrogen treatment is performed at a wafer temperature of from 200°

C. to 350°

C.

21. The method of claim 8, wherein atomic hydrogen treatment is performed at a wafer temperature of from 250°

C. to 300°

C.

22. The method of claim 8, wherein atomic hydrogen treatment is performed at a wafer temperature of about 280°

C.

23. The method of claim 8, wherein atomic hydrogen treatment is performed using catalytic conversion of H₂.

24. The method of claim 10, wherein the UV assisted thermal curing step is performed at a temperature of from 300°

C. to 500°

C.

25. The method of claim 10, wherein the UV assisted thermal curing step is performed at a temperature of from 350°

C. to 450°

C.

26. The method of claim 10, wherein the UV assisted thermal curing step is performed at a temperature of about 430°

C.

27. The method of claim 16, wherein the enhancer is selected from the group consisting of He, Ne, Ar, Kr, Xe, and combinations thereof, and wherein a ratio of enhancer to hydrogen is preferably from 1:

1 to 50;

1.

28. The method of claim 16, wherein the enhancer is selected from the group consisting of He, Ne, Ar, Kr, Xe, and combinations thereof, and wherein a ratio of enhancer to hydrogen is preferably from 10:

1 to 30;

1.

29. The method of claim 16, wherein the enhancer is selected from the group consisting of He, Ne, Ar, Kr, Xe, and combinations thereof, and wherein a ratio of enhancer to hydrogen is 20:

1.

30. A low-k film prepared by the method of claim 1, the film having a k-value of from 1.8 to 2.6, a porosity of from 41% to 60%, an elastic modulus of above 2 GPa, a thickness of a multiple of from 60 nm to 140 nm, an open porosity of less than 40%, and an average pore radius of from 0.6 nm to 3.0 nm.

31. A low-k film, the film having a k-value of from 1.8 to 2.6, a porosity of from 41% to 60%, an elastic modulus of above 2 GPa, a thickness of a multiple of from 60 nm to 140 nm, an open porosity of less than 40%, and an average pore radius of from 0.6 to 3.0 nm.

32. The low-k film of claim 31, having a k of greater than 2.0, a porosity higher than 48%, an elastic modulus of above 5 GPa, an open porosity of from 32% to 36%, and an average pore radius of from 0.7 nm to 2.0 nm.

33. The low-k film of claim 32, having an elastic modulus of above 7 GPa and an average pore radius of from 0.8 nm to 1.8 nm.

34. The low-k film of claim 32, having an elastic modulus of 9.5 GPa and an average pore radius of from 1.5 nm to 1.8 nm.

35. The low-k film of claim 31, which is an interlayer dielectric or intermetal dielectric.

36. An electronic element selected from the group consisting of a diode, a transistor, a MEMS, and a capacitor, the electronic element comprising the low-k film of claim 31.

37. A semiconductor device comprising the low-k film of claim 31.

38. An integrated circuit comprising the low-k film of claim 31.

39. An electronic component or a piece of electronic equipment, wherein the electronic component or piece of electronic equipment is selected from the group consisting of an RFID, a television, an audio device, a video device, a telephone, and a microphone, and wherein the electronic component or piece of electronic equipment comprises an electronic element, a semiconductor device, or an integrated circuit comprising the low-k film of claim 31.