METHODS OF FORMING ASYMMETRIC SPACERS ON VARIOUS STRUCTURES ON INTEGRATED CIRCUIT PRODUCTS

• US 20140248778A1
• Filed: 03/01/2013
• Published: 09/04/2014
• Est. Priority Date: 03/01/2013
• Status: Active Grant

• Current Assignee: Globalfoundries US Incorporated (GlobalFoundries, Inc.)
• Original Assignee: GlobalFoundries, Inc.
• Inventors: Moll, Hans-Peter, Patzer, Joachim
• Granted Patent: US 8,889,022 B2
• Time in Patent Office: Days
• US Class Current: 438/696
• CPC Class Codes: H01L 21/02107 Forming insulating materials on a substrate
• CPC Class Codes: H01L 21/32105 Oxidation of silicon-containing layers
• CPC Class Codes: H01L 21/32134 by liquid etching only
• CPC Class Codes: H01L 21/32137 of silicon-containing layers
• CPC Class Codes: H01L 21/32155 Doping polycristalline - or amorphous silicon layers
• CPC Class Codes: H01L 21/823468 with a particular manufacturing method of the gate sidewall spacers, e.g. double spacers, particular spacer material or shape
• CPC Class Codes: H01L 21/823864 with a particular manufacturing method of the gate sidewall spacers, e.g. double spacers, particular spacer material or shape
• CPC Class Codes: H01L 29/6653 using the removal of at least part of spacer, e.g. disposable spacer
• CPC Class Codes: H01L 29/66659 with asymmetry in the channel direction, e.g. lateral high-voltage MISFETs with drain offset region, extended drain MISFETs

Abstract

One illustrative method disclosed herein includes forming a structure above a semiconductor substrate, performing a conformal deposition process to form a layer of undoped spacer material above the structure, performing an angled ion implant process to form a region of doped spacer material in the layer of undoped spacer material while leaving other portions of the layer of undoped spacer material undoped, and, after performing the angled ion implant process, performing at least one etching process that removes the undoped portions of the layer of undoped spacer material and thereby results in a sidewall spacer comprised of the doped spacer material positioned adjacent at least one side, but not all sides, of the structure.

Claims

1. A method, comprising:

forming a structure above a semiconductor substrate;

performing a conformal deposition process to form a layer of undoped spacer material above said structure;

performing an angled ion implant process to form a region of doped spacer material in said layer of undoped spacer material while leaving other portions of said layer of undoped spacer material undoped; and

after performing said angled ion implant process, performing at least one etching process that removes said undoped portions of said layer of undoped spacer material and thereby results in a sidewall spacer comprised of said doped spacer material positioned adjacent at least one side, but not all sides, of said structure.

2. The method of claim 1, further comprising, prior to forming said layer of undoped spacer material, forming a protection layer on said structure and said substrate, said layer of undoped spacer material being formed on said protection layer.

3. The method of claim 1, wherein said layer of undoped spacer material is comprised of undoped amorphous silicon.

4. The method of claim 1, wherein said angled ion implant process is performed at an angle that falls within the range of about 5-45 degrees relative to a line normal to an upper surface of said substrate.

5. The method of claim 1, wherein said angled ion implant process is performed using one of boron difluoride, boron or carbon.

6. The method of claim 1, wherein said angled ion implant process is performed using a dopant dose that ranges from about 1e¹⁴-1e¹⁵ ions/cm² and at an energy level that ranges from about 1-20 keV.

7. The method of claim 1, further comprising performing a heating process to convert at least a portion of said sidewall spacer to an oxide material.

8. The method of claim 7, wherein said heating process is performed in one of a furnace or an RTA chamber.

9. The method of claim 1, wherein performing at least one etching process comprises:

performing a first etching process that selectively removes said undoped portions of said layer of undoped spacer material while leaving said region of doped spacer material in position; and

performing a second anisotropic etching process to remove portions of said region of doped spacer material so as to thereby define said sidewall spacer.

10. The method of claim 1, wherein said structure comprises a gate electrode structure for a transistor.

11. The method of claim 1, wherein said sidewall spacer is positioned adjacent only one side of said structure.

12. The method of claim 1, wherein said sidewall spacer is positioned adjacent only two sides of said structure.

13. The method of claim 1, further comprising performing an additional angled ion implant process, wherein said sidewall spacer is positioned adjacent only three sides of said structure.

14. A method, comprising:

forming a structure above a semiconductor substrate;

performing a conformal deposition process to form a layer of undoped spacer material above said structure;

performing an angled ion implant process with dopant material comprised of one of boron difluoride, boron or carbon to form a region of doped spacer material comprising said dopant material in said layer of undoped spacer material while leaving other portions of said layer of undoped spacer material undoped;

after performing said angled ion implant process, performing a first etching process that selectively removes said undoped portions of said layer of undoped spacer material while leaving said region of doped spacer material in position; and

performing a second anisotropic etching process to remove portions of said region of doped spacer material that are oriented in a direction that is substantially parallel to an upper surface of said substrate so as to thereby define a sidewall spacer comprised of said doped spacer material positioned adjacent at least one side, but not all sides, of said structure.

15. The method of claim 14, further comprising, prior to forming said layer of undoped spacer material, forming a protection layer on said structure and said substrate, said layer of undoped spacer material being formed on said protection layer.

16. The method of claim 14, wherein said layer of undoped spacer material is comprised of undoped amorphous silicon.

17. The method of claim 14, wherein said angled ion implant process is performed at an angle that falls within the range of about 5-45 degrees relative to a line normal to an upper surface of said substrate.

18. The method of claim 14, wherein said angled ion implant process is performed using a dopant dose that ranges from about 1e¹⁴-1e¹⁵ ions/cm² and at an energy level that ranges from about 1-20 keV.

19. The method of claim 14, further comprising performing a heating process to convert at least a portion of said sidewall spacer to an oxide material.

20. A method, comprising:

forming a structure above a semiconductor substrate;

performing a conformal deposition process to form a layer of undoped spacer material above said structure, wherein said layer of undoped spacer material is comprised of undoped amorphous silicon;

performing an angled ion implant process with dopant material comprised of one of boron difluoride, boron or carbon to form a region of doped spacer material comprising said dopant material in said layer of undoped spacer material while leaving other portions of said layer of undoped spacer material undoped, wherein said angled ion implant process is performed at an angle that falls within the range of about 5-45 degrees relative to a line normal to an upper surface of said substrate and using a dopant dose that ranges from about 1e¹⁴-1e¹⁵ ions/cm²;

after performing said angled ion implant process, performing a first etching process that selectively removes said undoped portions of said layer of undoped spacer material while leaving said region of doped spacer material in position; and

performing a second anisotropic etching process to remove portions of said region of doped spacer material that are oriented in a direction that is substantially parallel to an upper surface of said substrate so as to thereby define a sidewall spacer comprised of said doped spacer material positioned adjacent at least one side, but not all sides, of said structure.

21. The method of claim 20, further comprising, prior to forming said layer of undoped spacer material, forming a protection layer on said structure and said substrate, said layer of undoped spacer material being formed on said protection layer.

22. The method of claim 20, wherein said angled ion implant process is performed at an energy level that ranges from about 1-20 keV.

23. The method of claim 20, further comprising performing a heating process to convert at least a portion of said sidewall spacer to an oxide material.