Method for treating non-planar structures using gas cluster ion beam processing

• US 8,048,788 B2
• Filed: 10/08/2009
• Issued: 11/01/2011
• Est. Priority Date: 10/08/2009
• Status: Active Grant

• Current Assignee: TEL Manufacturing and Engineering of America, Inc.
• Original Assignee: TEL Epion Inc. (Tokyo Electron Limited)
• Inventors: Hautala, John J., Russell, Noel
• Primary Examiner(s): Geyer; Scott B
• Application Number:
  US12/575,887
• Publication Number:
  US 20110084216A1
• Time in Patent Office: 754 Days
• Field of Search: None
• US Class Current: 438/514
• CPC Class Codes: C23C 14/221 Ion beam deposition C23C14/46, C23C14/48 take precedence
• CPC Class Codes: C23C 14/50 Substrate holders
• CPC Class Codes: H01J 2237/31701 Ion implantation
• CPC Class Codes: H01J 2237/3171 patterned
• CPC Class Codes: H01J 2237/31732 Depositing thin layers on selected microareas ion plating H01J2237/3142
• CPC Class Codes: H01J 2237/3174 Etching microareas
• CPC Class Codes: H01J 37/3053 for evaporating or etching
• CPC Class Codes: H01J 37/3178 for applying thin layers on objects
• CPC Class Codes: H01L 21/26513 of electrically active species
• CPC Class Codes: H01L 21/26566 of a cluster, e.g. using a gas cluster ion beam
• 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 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
• CPC Class Codes: H01L 29/785 having a channel with a horizontal current flow in a vertical sidewall of a semiconductor body, e.g. FinFET, MuGFET

Abstract

A method for treating a structure is described. One embodiment includes forming a structure on a substrate, wherein the structure has a plurality of surfaces including one or more first surfaces lying substantially parallel to a first plane parallel with said substrate and one or more second surfaces lying substantially perpendicular to the first plane. Additionally, the method comprises directing a gas cluster ion beam (GCIB) formed from a material source toward the substrate with a direction of incidence, and orienting the substrate relative to the direction of incidence. The method further comprises treating the one or more second surfaces.

Claims

1. A method for treating a structure, comprising:

forming said structure on a substrate, said structure having a plurality of surfaces including one or more first surfaces lying substantially parallel to a first plane parallel with said substrate, and one or more second surfaces lying substantially perpendicular to said first plane;

growing and/or depositing a screening layer on at least a portion of said one or more first surfaces;

thereafter, directing a gas cluster ion beam (GCIB) formed from a material source toward said substrate with a controlled directionality to place at least said one or more second surfaces in a path of said GCIB, wherein said directionality is controlled by orienting said substrate relative to a direction of incidence of said GCIB and/or adjusting a beam divergence of said GCIB; and

treating at least said one or more second surfaces with said GCIB, wherein said screening layer is at least partially in said path of said GCIB and has a thickness greater than a penetration depth of said GCIB whereby treatment by said GCIB is avoided in said at least a portion of said one or more first surfaces underlying said screening layer.

2. The method of claim 1, wherein said structure comprises a via, a contact, a trench, a film stack, a fin, a multi-gate field-effect transistor (MuFET), or a fin field-effect transistor (FinFET).

3. The method of claim 1, wherein said treating at least said one or more second surfaces comprises doping said one or more second surfaces, etching said one or more second surfaces, cleaning said one or more second surfaces, depositing a thin film on said one or more second surfaces, growing a thin film on said one or more second surfaces, modifying a property of said one or more second surfaces, or smoothing said one or more second surfaces, or any combination of two or more thereof.

4. The method of claim 1, wherein said material source comprises one or more elements selected from the group consisting of B, C, Si, Ge, N, P, As, O, S, and Cl.

5. The method of claim 1, wherein said material source comprises a dopant and said treating comprises introducing said dopant into said one or more second surfaces to said penetration depth.

6. A method for treating a structure, comprising:

forming said structure on a substrate, said structure having a plurality of surfaces including one or more first surfaces lying substantially parallel to a first plane parallel with said substrate, and one or more second surfaces lying substantially perpendicular to said first plane;

forming a gas cluster ion beam (GCIB) from a material source comprising a dopant and selecting a beam energy, a beam energy distribution, a beam focus, and a beam dose to achieve a desired penetration depth of said dopant in said one or more second surfaces;

accelerating said GCIB to achieve said beam energy;

focusing said GCIB to achieve said beam focus;

directing said accelerated GCIB toward at least a portion of said substrate with a direction of incidence and according to said beam dose;

orienting said substrate relative to said direction of incidence; and

treating said one or more second surfaces with said GCIB to introduce said dopant to said at least a portion of said substrate to achieve said desired penetration depth.

7. The method of claim 6, further comprising:

adjusting a first amount of said dopant introduced to said one or more first surfaces and/or a second amount of said dopant introduced to said one or more second surfaces by modifying said beam energy, modifying said beam energy distribution, modifying said beam focus, modifying said beam dose, or adjusting an orientation of said substrate relative to said direction of incidence, or any combination of two or more thereof.

8. A method for preparing a gate structure, comprising:

forming a fin on a substrate;

introducing a dopant into a sidewall of said fin using a gas cluster ion beam (GCIB); and

forming a screening layer on a top surface of said fin prior to said introducing said dopant to said sidewall.

9. The method of claim 8, wherein said introducing said dopant comprises introducing one or more elements selected from the group consisting of B, C, Si, Ge, N, P, As, O, S, and Cl.

10. The method of claim 8, wherein said forming said screening layer comprises using another GCIB to grow and/or deposit said screening layer.

11. The method of claim 8, wherein said forming said screening layer comprises using a thermal oxidation process, a vapor deposition process, a sputter deposition, a physical vapor deposition process, an ionized physical vapor deposition process, a chemical vapor deposition process, or a plasma-enhanced chemical vapor deposition process.

12. The method of claim 8, wherein said forming said screening layer comprises growing and/or depositing a layer of silicon oxide (SiO_x), silicon nitride (SiN_y), silicon oxynitride (SiO_xN_y), silicon-germanium (SiGe), or germanium (Ge).

16. The method of claim 8, wherein said fin is adapted for use as a source or drain for a multi-gate field-effect transistor (MuFET), or a fin field-effect transistor (FinFET).

13. The method of 8, further comprising:

selecting a beam energy, a beam energy distribution, a beam focus, and a beam dose to achieve a desired penetration depth of said dopant in said sidewall of said fin;

accelerating said GCIB to achieve said beam energy;

focusing said GCIB to achieve said beam focus;

irradiating at least a portion of said substrate with said accelerated GCIB according to said beam dose; and

introducing said dopant in said sidewall of said fin to achieve said desired penetration depth.

14. The method of claim 13, further comprising:

adjusting a first amount of said dopant in said screening layer and/or a second amount of said dopant in said sidewall by modifying said beam energy, modifying said beam energy distribution, modifying said beam focus, modifying said beam dose, or adjusting an orientation of said substrate relative to a direction of incidence of said GCIB, or any combination of two or more thereof.

15. The method of claim 13, further comprising:

adjusting a first amount of said dopant in said screening layer, or a second amount of said dopant in said sidewall, or any combination of two or more thereof, by adjusting a beam divergence of said GCIB.

17. A method for preparing a gate structure, comprising:

forming a fin on a substrate;

forming a screening layer on a top surface of said fin using a gas cluster ion beam (GCIB); and

introducing a dopant into a sidewall of said fin following said forming said screening layer.

18. The method of claim 17, wherein said introducing said dopant into said sidewall comprises performing an ion implantation process or a plasma immersion ion implantation process.

19. The method of claim 17, wherein said introducing said dopant comprises introducing one or more elements selected from the group consisting of B, C, Si, Ge, N, P, As, O, S, and Cl.