Process for depositing a material on a substrate using light energy

• US 5,820,942 A
• Filed: 12/20/1996
• Issued: 10/13/1998
• Est. Priority Date: 12/20/1996
• Status: Expired due to Fees

• Current Assignee: STEAG RTP Systems, Inc. (KSBG Kommunale Beteiligungsgesellschaft GmbH & Company KG)
• Original Assignee: AG Associates Incorporated (KSBG Kommunale Beteiligungsgesellschaft GmbH & Company KG)
• Inventors: Singh, Rajendra, Sharangpani, Rahul
• Primary Examiner(s): PIANALTO, BERNARD D
• Application Number:
  US08/770,907
• Time in Patent Office: 662 Days
• Field of Search: 427/475, 427/485, 427/508, 427/557, 427/558, 427/559, 427/561, 427/582, 427/595, 427/294, 427/385.5, 427/421, 427/96, 427/512
• US Class Current: 427/508
• CPC Class Codes: H01L 21/02107 Forming insulating materials on a substrate
• CPC Class Codes: H01L 21/0212 the material being fluoro carbon compounds, e.g.(CFx) n, (CHxFy) n or polytetrafluoroethylene
• CPC Class Codes: H01L 21/02205 the layer being characterised by the precursor material for deposition
• CPC Class Codes: H01L 21/02282 liquid deposition, e.g. spin-coating, sol-gel techniques, spray coating
• CPC Class Codes: H01L 21/02348 treatment by exposure to UV light
• CPC Class Codes: H01L 21/316 composed of oxides or glassy oxides or oxide based glass

Abstract

The present invention is generally directed to a process and a system for transforming a liquid into a solid material using light energy. In particular, a solution containing a parent material in a liquid form is atomized in a reaction vessel and directed towards a substrate. The atomized liquid is exposed to light energy which causes the parent material to form a solid coating on a substrate. The light energy can be provided from one or more lamps and preferably includes ultraviolet light. Although the process of the present invention is well suited for use in many different and various applications, one exemplary application is in depositing a dielectric material on a substrate to be used in the manufacture of integrated circuit chips.

Claims

1. A process for forming an electrical insulating layer in an integrated circuit comprising the steps of:

providing a solution containing an electrical insulating material and a solvent, said electrical insulating material comprising an amorphous fluorocarbon polymer;

atomizing said solution into droplets, said droplets being released into a processing chamber, said processing chamber containing a substrate comprising a semiconductive material, said droplets being deposited onto said substrate;

exposing said processing chamber to a combination of a first light energy source and a second light energy source while said droplets are being deposited on said substrate, said first light energy source emitting ultraviolet light energy, said second light energy source emitting thermal light energy, said light energy causing said amorphous fluorocarbon polymer to polymerize and form a solid coating on said substrate, said solid coating having a dielectric constant of less than about three.

2. A process as defined in claim 1, wherein said substrate comprises a silicon wafer.

3. A process as defined in claim 1, wherein said amorphous fluorocarbon polymer comprises a copolymer of tetrafluoroethylene and 2,2-bis(trifluoromethyl)-4,5-difluoro-1,3-dioxole.

4. A process as defined in claim 1, wherein said thermal light energy emitted by said second light energy source is primarily directed onto said substrate, and wherein said ultraviolet light energy being emitted by said first light energy source is primarily directed towards said droplets as said droplets are being deposited onto said substrate.

5. A process as defined in claim 1, further comprising the step of preheating said processing chamber to a temperature of at least 50°

C. prior to releasing said droplets into said chamber.

6. A process as defined in claim 5, wherein said processing chamber is preheated to a temperature of at least 100°

C.

7. A process as defined in claim 1, wherein said solvent comprises a fluorocarbon.

8. A process as defined in claim 1, wherein said light energy causes substantially all of said solvent contained within said droplets to evaporate prior to said amorphous fluorocarbon polymer being deposited onto said substrate.

9. A process as defined in claim 1, further comprising the step of maintaining a vacuum in said processing chamber as said droplets are deposited onto said substrate.

10. A process as defined in claim 1, wherein said first light energy source emits vacuum ultraviolet light energy.

11. A process as defined in claim 1, wherein said solid coating of said amorphous fluorocarbon polymer that is deposited onto said substrate has a thickness of from about 1 monolayer to about 1 micron.

12. A process as defined in claim 1, wherein said thermal light energy being emitted by said second light energy source has a wavelength greater than about 0.8 microns.

13. A process as defined in claim 1, wherein said light energy causes an attraction to occur between said amorphous fluorocarbon polymer and said substrate.

14. A process as defined in claim 1, wherein said droplets enter said processing chamber above said substrate.

15. A process for forming an electrical insulating layer in an integrated circuit comprising the steps of:

providing a solution containing an electrical insulating material in a liquid form, said electrical insulating material comprising a material selected from the group consisting of a fluorocarbon polymer and a polyimide polymer;

atomizing said solution into liquid droplets;

directing said liquid droplets into a processing chamber towards a substrate;

exposing said processing chamber to a combination of optical light energy and thermal light energy prior to said liquid droplets contacting said substrate, said light energy causing atomic and molecular excitation and said thermal light energy causing vibrational motion of molecules, said light energy causing said electrical insulating material to polymerize and form a solid coating on said substrate, said solid coating having a dielectric constant of less than about three.

16. A process as defined in claim 15, wherein a first light energy source primarily emits said optical light energy, and a second light energy source primarily emits said thermal light energy.

17. A process as defined in claim 16, wherein said optical light energy comprises ultraviolet light.

18. A process as defined in claim 16, wherein said thermal light energy being emitted by said second light energy source is primarily directed towards said substrate, while said optical light energy being emitted by said first light energy source is primarily directed towards said liquid droplets as said droplets are deposited onto said substrate.

19. A process as defined in claim 15, wherein said optical light energy comprises vacuum ultraviolet light.

20. A process as defined in claim 15, wherein said light energy causes substantially all of said solvent contained within said liquid droplets to evaporate prior to said electrical insulating material contacting said substrate.

21. A process as defined in claim 15, wherein said electrical insulating material comprises an amorphous fluorocarbon copolymer.

22. A process as defined in claim 21, wherein said amorphous fluorocarbon copolymer comprises a copolymer of tetrafluoroethylene and 2,2-bis(trifluoromethyl)-4,5-difluoro-1,3-dioxole.

23. A process as defined in claim 15, wherein said substrate comprises a silicon wafer.

24. A process as defined in claim 15, further comprising the step of preheating said processing chamber to a temperature of at least 50°

C. prior to atomizing said solution.

25. A process as defined in claim 15, further comprising the step of annealing said solid coating on said substrate at a temperature of at least 200°

C. using light energy.

26. A process for forming an electrical insulating layer in an integrated circuit comprising the steps of:

providing a solution containing an electrical insulating material and a solvent;

atomizing said solution into droplets, said droplets being released into a processing chamber, said processing chamber containing a substrate comprising a semiconductive material, said droplets being deposited onto said substrate; and

exposing said processing chamber to a combination of optical light energy and thermal light energy while said droplets are being deposited onto said substrate, said light energy causing substantially all of said solvent contained within said droplets to evaporate prior to said electrical insulating material contacting said substrate, said light energy also causing said electrical insulating material to polymerize and form a continuous solid coating on said substrate, said solid coating having a dielectric constant of less than about three.

27. A process as defined in claim 26, wherein a first light energy source primarily emits said optical light energy, while a second light energy source primarily emits said thermal light energy.

28. A process as defined in claim 27, wherein said optical light energy comprises ultraviolet light.

29. A process as defined in claim 27, wherein said thermal light energy being emitted by said second light energy source is primarily directed towards said substrate, while said optical light energy being emitted by said first light energy source is primarily directed towards said liquid droplets as said droplets are being deposited onto said substrate.

30. A process as defined in claim 26, wherein said optical light energy comprises vacuum ultraviolet light.

31. A process as defined in claim 26, further comprising the step of preheating said processing chamber to a temperature of at least 50°

C. prior to atomizing said solution.

32. A process as defined in claim 26, wherein said electrical insulating material comprises a material selected from the group consisting of a fluorocarbon polymer and a polyimide polymer.

33. A process as defined in claim 26, wherein said electrical insulating material comprises an amorphous fluorocarbon copolymer.

34. A process as defined in claim 33, wherein said amorphous fluorocarbon copolymer comprises a copolymer of tetrafluoroethylene and 2,2-bis(trifluoromethyl)-4,5-difluoro-1,3-dioxole.

35. A process for forming an electrical insulating layer in an integrated circuit comprising the steps of:

providing a solution containing an electrical insulating material and a solvent;

atomizing said solution into droplets, said droplets being released into a processing chamber, said processing chamber containing a substrate comprising a semiconductive material, said droplets being deposited onto said substrate; and

exposing said processing chamber to light energy as said droplets are deposited onto said substrate, said light energy comprising vacuum ultraviolet light, said vacuum ultraviolet light causing said electrical insulating material to polymerize and form a solid coating on said substrate.

36. A process as defined in claim 35, wherein said processing chamber is also exposed to thermal light energy while said droplets are being deposited onto said substrate.

37. A process as defined in claim 36, wherein a first light energy source emits said vacuum ultraviolet light and a second light energy source emits said thermal light energy, said thermal light energy being directed primarily at said substrate while said vacuum ultraviolet light being directed primarily at said droplets as said droplets are being deposited onto said substrate.

38. A process as defined in claim 35, wherein said electrical insulating material comprises a material selected from the group consisting of a fluorocarbon polymer and a polyimide polymer.

39. A process as defined in claim 35, wherein said electrical insulating material comprises an amorphous fluorocarbon copolymer.

40. A process as defined in claim 35, wherein substantially all of said solvent contained within said liquid droplets is evaporated prior to said electrical insulating material contacting said substrate.