Method for producing low-permittivity spacers

1. A method for manufacturing a transistor using a stack comprising at least one gate pattern comprising at least one flank and being located above an underlying layer made of a semi-conductor material, the method comprising the following successive steps:

forming, at least partially, at least one gate spacer by depositing at least one layer made of a non-carbon material on the at least one flank of the at least one gate pattern;

after the depositing of the at least one layer made of a non-carbon material, performing at least one step of exposing the stack to a temperature greater than or equal to 600° C.;

after the at least one step of exposing, performing at least one step of reducing of a dielectric permittivity of the at least one gate spacer, the reducing comprising at least one ion implantation in a portion at least of a thickness of the at least one gate spacer,

wherein parameters of the at least one ion implantation including species implanted, energy, and implantation dose, being chosen such that the at least one ion implantation reduces the dielectric permittivity of the at least one gate spacer, and

wherein, during the at least one ion implantation, the at least one gate spacer is present only on the at least one gate pattern; and

at least one step of forming at least one source/drain zone in a peripheral zone surrounding the at least one gate pattern and located above the underlying layer, wherein the at least one step of forming of the at least one source/drain zone comprises

the at least one step of exposing the stack to the temperature greater than or equal to 600° C., and

a step of epitaxy of the at least one source/drain zone.

2. The method according to claim 1 ,

wherein the step of forming the at least one source/drain zone further comprises an activation annealing of the at least one source/drain zone, and

wherein the annealing comprises the at least one step of exposing at the temperature greater than or equal to 600° C.

3. The method according to claim 1 ,

wherein the step of forming the at least one source/drain zone further comprises a step of epitaxy of the at least one source/drain zone, and

wherein the step of epitaxy comprises said at least one step of exposing at the temperature greater than or equal to 600° C.

4. The method according to claim 1 , wherein during the step of forming of the at least one source/drain zone, the at least one gate spacer has already been entirely formed.

5. The method according to claim 1 , further comprising at least one step of silicidation of electrical contacts on a gate of the transistor and/or on the at least one source/drain zone, wherein the at least one step of silicidation comprises the at least one step of exposing at the temperature greater than or equal to 600° C.

6. The method according to claim 1 , further comprising at least one step of wet cleaning of surfaces of the stack, wherein the at least one step of cleaning is performed before the step of reducing the dielectric permittivity.

7. The method according to claim 1 , wherein the at least one ion implantation is performed with a base of ions with a hydrogen base or with a helium base.

8. The method according to claim 1 , wherein the at least one ion implantation is performed by plasma.

9. The method according to claim 1 , wherein the at least one ion implantation is performed by plasma at a pressure greater than or equal to 80 mTorr.

10. The method according to claim 1 , wherein the at least one ion implantation is performed by an implanter.

11. The method according to claim 1 , wherein the at least one ion implantation is performed so as to implant the at least one gate spacer over at least one portion of its thickness or so as to implant the at least one gate spacer over an entire thickness thereof.

12. The method according to claim 1 , wherein during the at least one ion implantation the at least one gate spacer is entirely formed.

13. The method according to claim 1 , wherein during the at least one ion implantation the at least one gate spacer is present only on the at least one gate pattern.

14. The method according to claim 1 , wherein during the at least one ion implantation the at least one gate spacer is present only on the at least one flank of the at least one gate pattern.

15. The method according to claim 1 , wherein the at least one gate spacer comprises at least one non-carbon material chosen from among SiN, BN, and SiO 2 .

16. The method according to claim 1 , wherein the at least one gate spacer comprises at least one material having a dielectric permittivity, after the step of reducing, of less than 7.

17. The method according to claim 1 , wherein the forming of the at least one gate spacer comprises depositing a first dielectric layer on the at least one flank of the at least one gate pattern so as to form at least one first level of spacers.

18. The method according to claim 17 , wherein the depositing of the first dielectric layer is followed by depositing of a second dielectric layer on the at least one first level of spacers of the at least one gate pattern so as to form at least one second level of spacers.

19. The method according to claim 1 , wherein the at least one gate pattern is a gate stack formed before the forming of the at least one gate spacer.

20. The method according to claim 17 , further comprising, after the forming of the at least one gate spacer, a step of removing of the at least one gate pattern so as to define a cavity between two spacers forming the at least one first level of spacers; and, after removing of the at least one gate pattern, a step of forming a gate stack.

21. The method according to claim 1 , wherein, before the forming of the at least one gate pattern, the underlying layer made of the semi-conductor material has a hollow between two zones intended to form source/drain zones, and further comprising at least one step of realizing the at least one gate pattern such that the at least one gate pattern is at least partially located in the hollow.

22. The method according to claim 1 , wherein the at least one gate stack is disposed between two spacers, and further comprising removing a portion of the at least one gate stack so as to define a cavity between the two spacers, wherein the at least one ion implantation is performed so as to implant at least one internal face of the two spacers, the at least one internal face being turned to face the cavity.

23. The method according to claim 18 ,

wherein the at least one ion implantation comprises a first ion implantation and a second ion implantation performed after the first ion implantation,

wherein the first ion implantation is performed to reduce a dielectric permittivity of the first level of spacers, and

wherein the at least one gate pattern is disposed between two spacers forming the first level of spacers,

the method further comprising removing the at least one gate pattern so as to define a cavity between the two spacers forming the first level of spacers,

wherein the first ion implantation is performed so as to implant at least one internal face of the first level of spacers, the internal face being turned to face the cavity, in order to reduce the dielectric permittivity of the first level of spacers.

24. The method according to claim 23 , wherein the second ion implantation is performed to reduce the dielectric permittivity of the second level of spacers.

25. The method according to claim 24 , further comprising exposing at least one external face of the second level of spacers,

wherein the second ion implantation is performed so as to implant the at least one external face of the second level of spacers so as to reduce the dielectric permittivity of the second level of spacers.

26. The method according to claim 23 , wherein the first ion implantation is performed after a first step of silicidation of electrical contacts on a gate of the transistor and/or on a source/drain zone of the transistor.

27. The method according to claim 23 , wherein the second ion implantation is performed after a second step of silicidation of electrical contacts on a gate of the transistor and/or on a source/drain zone of the transistor.

28. A method for manufacturing a transistor using a stack comprising at least one gate pattern comprising at least one flank and being located above an underlying layer made of a semi-conductor material, the method comprising the following successive steps:

forming, at least partially, at least one gate spacer by depositing at least one layer made of a non-carbon material on the at least one flank of the at least one gate pattern;

after the depositing of the at least one layer made of a non-carbon material, performing at least one step of exposing the stack to a temperature greater than or equal to 600° C.;

after the at least one step of exposing, performing at least one step of reducing of a dielectric permittivity of the at least one gate spacer, the reducing comprising at least one ion implantation in a portion at least of a thickness of the at least one gate spacer,

wherein parameters of the at least one ion implantation including species implanted, energy, and implantation dose, being chosen such that the at least one ion implantation reduces the dielectric permittivity of the at least one gate spacer,

wherein, during the at least one ion implantation, the at least one gate spacer is present only on the at least one gate pattern, and

wherein, before the forming of the at least one gate pattern, the underlying layer made of the semi-conductor material has a hollow between two zones intended to form source/drain zones; and

at least one step of realizing the at least one gate pattern such that the at least one gate pattern is at least partially located in the hollow.

29. A method for manufacturing a transistor using a stack comprising at least one gate pattern comprising at least one flank and being located above an underlying layer made of a semi-conductor material, the method comprising the following successive steps:

forming, at least partially, at least one gate spacer by depositing at least one layer made of a non-carbon material on the at least one flank of the at least one gate pattern;

after the depositing of the at least one layer made of a non-carbon material, performing at least one step of exposing the stack to a temperature greater than or equal to 600° C.;

after the at least one step of exposing, performing at least one step of reducing of a dielectric permittivity of the at least one gate spacer, the reducing comprising at least one ion implantation in a portion at least of a thickness of the at least one gate spacer,

wherein parameters of the at least one ion implantation including species implanted, energy, and implantation dose, being chosen such that the at least one ion implantation reduces the dielectric permittivity of the at least one gate spacer,

wherein, during the at least one ion implantation, the at least one gate spacer is present only on the at least one gate pattern,

wherein the at least one gate stack is disposed between two spacers; and

removing a portion of the at least one gate stack so as to define a cavity between the two spacers,

wherein the at least one ion implantation is performed so as to implant at least one internal face of the two spacers, the at least one internal face being turned to face the cavity.

30. A method for manufacturing a transistor using a stack comprising at least one gate pattern comprising at least one flank and being located above an underlying layer made of a semi-conductor material, the method comprising the following successive steps:

forming, at least partially, at least one gate spacer by depositing at least one layer made of a non-carbon material on the at least one flank of the at least one gate pattern;

after the depositing of the at least one layer made of a non-carbon material, performing at least one step of exposing the stack to a temperature greater than or equal to 600° C.;

after the at least one step of exposing, performing at least one step of reducing of a dielectric permittivity of the at least one gate spacer, the reducing comprising at least one ion implantation in a portion at least of a thickness of the at least one gate spacer,

wherein parameters of the at least one ion implantation including species implanted, energy, and implantation dose, being chosen such that the at least one ion implantation reduces the dielectric permittivity of the at least one gate spacer, and

wherein, during the at least one ion implantation, the at least one gate spacer is present only on the at least one gate pattern,

wherein the forming of the at least one gate spacer comprises depositing a first dielectric layer on the at least one flank of the at least one gate pattern so as to form at least one first level of spacers,

wherein the depositing of the first dielectric layer is followed by depositing of a second dielectric layer on the at least one first level of spacers of the at least one gate pattern so as to form at least one second level of spacers,

wherein the at least one ion implantation comprises a first ion implantation and a second ion implantation performed after the first ion implantation,

wherein the first ion implantation is performed to reduce a dielectric permittivity of the first level of spacers, and

wherein the at least one gate pattern is disposed between two spacers forming the first level of spacers; and

removing the at least one gate pattern so as to define a cavity between the two spacers forming the first level of spacers,

wherein the first ion implantation is performed so as to implant at least one internal face of the first level of spacers, the internal face being turned to face the cavity, in order to reduce the dielectric permittivity of the first level of spacers.