Technique for selectively processing three dimensional device

• US 9,337,314 B2
• Filed: 12/11/2013
• Issued: 05/10/2016
• Est. Priority Date: 12/12/2012
• Status: Active Grant

• Current Assignee: Varian Semiconductor Equipment Associates Incorporated (Applied Materials Incorporated)
• Original Assignee: Varian Semiconductor Equipment Associates Incorporated (Applied Materials Incorporated)
• Inventors: Pradhan, Nilay A., Colombeau, Benjamin, Variam, Naushad K., Pandit, Mandar B., Bencher, Christopher Dennis, Brand, Adam
• Primary Examiner(s): Tsai, H
• Application Number:
  US14/103,329
• Publication Number:
  US 20140162414A1
• Time in Patent Office: 881 Days
• Field of Search: 438156-166, 438/714, 438/725
• US Class Current: 1/1
• CPC Class Codes: H01L 21/26513 of electrically active species
• CPC Class Codes: H01L 21/26586 characterised by the angle between the ion beam and the crystal planes or the main crystal surface
• CPC Class Codes: H01L 21/31122 of layers not containing Si, e.g. PZT, Al2O3
• CPC Class Codes: H01L 29/66795 with a horizontal current flow in a vertical sidewall of a semiconductor body, e.g. FinFET, MuGFET
• CPC Class Codes: H01L 29/66803 with a step of doping the vertical sidewall, e.g. using tilted or multi-angled implants

Abstract

A method to selectively process a three dimensional device, comprising providing a substrate having a first surface that extends horizontally, the substrate comprising a structure containing a second surface that extends vertically from the first surface; providing a film on the substrate, the film comprising carbon species; and etching a selected portion of the film by exposing the selected portion of the film to an etchant containing hydrogen species, where the etchant excludes oxygen species and fluorine species.

Claims

1. A method to selectively process a three dimensional device, comprising:

providing a substrate having a first surface that extends horizontally, the substrate comprising a fin structure containing a second surface that extends vertically from the first surface;

providing a film atop and in direct contact with the fin structure of the substrate, the film comprising carbon species, and the substrate and the fin structure comprising a semiconductor material including silicon; and

etching a selected portion of the film selective to the fin structure of the substrate by exposing the selected portion of the film to an etchant containing hydrogen species, the etchant excluding oxygen species and fluorine species.

2. The method of claim 1, wherein the carbon species contains at least one of graphitic and amorphous structure.

3. The method of claim 1, wherein the carbon species contains a mixture of sp1, sp2, and sp3 bonding.

4. The method of claim 1, wherein the film comprises a stress having a value less than 0.1 gigapascal.

5. The method of claim 1, wherein the etchant comprises hydrogen or hydrogen diluted with inert gas, nitrogen or both, and wherein the carbon species is removed through a C—

H chemical reduction process.

6. The method of claim 1, further comprising implanting the fin structure with a dopant species.

7. The method of claim 6, further comprising maintaining a temperature of the substrate at a substrate temperature of 400°

C. or higher during the implanting.

8. The method of claim 6, wherein the fin structure comprises a portion of a FinFET device, the implanting comprising performing a first implant to implant a first dopant species of a first type when an unetched portion of the film is disposed on the portion of the FinFET device.

9. The method of claim 8, wherein the film is a first film, the selected portion of the film is a first selected portion that is disposed on a first region of the substrate, the method further comprising:

removing the unetched portion of the film after the first implant;

depositing a second film comprising carbon species on the substrate;

etching a second selected portion of the second film that is disposed on a second region of the substrate different from the first region by exposing the second selected portion of the film to an etchant containing hydrogen species; and

performing a second implant to implant second dopant species of a second dopant type different from the first dopant type when an unetched portion of the second film is disposed on the FinFET device.

10. The method of claim 1, wherein the etching the selected portion of the film comprises:

depositing a photoresist material on the film;

removing the photoresist material from a region adjacent the selected portion; and

etching the selected portion while the photoresist is disposed on another portion of the film.

11. The method of claim 1, wherein the etching the selected portion of the film does not etch silicon, silicon oxide or silicon nitride.

12. A method to process a FinFET device, comprising:

providing a substrate having a first surface that extends horizontally, the substrate comprising a fin structure having a pair of opposed surfaces extending vertically from the first surface;

providing a film atop and in direct contact with the fin structure of the substrate, the film comprising carbon species, and the substrate and the fin structure comprising a semiconductor material including silicon;

etching a selected portion of the film that covers the fin structure, selective to the fin structure of the substrate, by exposing the selected portion of the film to an etchant containing hydrogen species and excluding oxygen species and fluorine species, wherein an exposed fin region is formed on the fin structure; and

performing an ion implantation process into the exposed fin region to introduce a dopant at a substrate temperature of greater than 300°

C.

13. The method of claim 12, wherein the carbon species contains at least one of graphitic and amorphous structure having a mixture of sp1, sp2, and sp3 bonding.

14. The method of claim 12, wherein the etchant comprising hydrogen or hydrogen diluted with inert gas, nitrogen, or both, wherein the carbon species is removed through a C—

H chemical reduction process.

15. The method of claim 12, wherein the film is a first film, the selected portion of the film is a first selected portion that is disposed on a first region of the substrate and the exposed fin region is a first exposed fin region, the method further comprising:

removing the unetched portion of the film after the first implant;

depositing a second film comprising carbon species on the substrate;

etching a second selected portion of the second film that is disposed on a second region of the substrate different from the first region by exposing the second selected portion of the film to an etchant containing hydrogen species, wherein a second exposed fin region is formed; and

performing a second implant to implant second dopant species of a second dopant type different from the first dopant type into the exposed fin region.

16. The method of claim 12, wherein the etching the selected portion of the film does not etch silicon, silicon oxide or silicon nitride.

17. The method of claim 12, wherein the performing the implantation process comprises implanting the dopant species at a dose of 1E14 cm⁻

2 to 1E16 cm<sup>−

2</sup>.

18. The method of claim 12, further comprising performing an annealing process after the performing the implantation process, wherein the exposed fin region comprises a single crystalline material after the annealing process.

19. The method of claim 18, wherein the peak dopant concentration of the activated dopant layer is 1E20/cm³ or higher.