Method for forming a nanowire device
A method of forming a nanowire device includes providing a substrate containing nanowires between vertical spacers, selectively depositing a high-k film on the nanowires relative to the vertical spacers, and selectively depositing a metal-containing gate electrode layer on the high-k film relative to the vertical spacers. The method can further include selectively depositing a dielectric material on the vertical spacers prior to selectively depositing the high-k film, where the dielectric material has a lower dielectric constant than the high-k film.
1. A method of forming a nanowire device, the method comprising:
providing a substrate containing nanowires between vertical spacers;
selectively depositing a high-k film on the nanowires relative to the vertical spacers; and
selectively depositing a metal-containing gate electrode layer on the high-k film relative to the vertical spacers.
2. The method of claim 1 , further comprising:
selectively depositing a dielectric material on the vertical spacers prior to selectively depositing the high-k film, wherein the dielectric material has a lower dielectric constant than the high-k film.
3. The method of claim 2 , wherein selectively depositing the dielectric material on the vertical spacers includes depositing sufficient dielectric material to reduce gate-to-drain capacitance in the nanowire device.
4. The method of claim 1 , further comprising:
depositing a dielectric material on the vertical spacers above the nanowires after selectively depositing the metal-containing gate electrode layer, wherein the dielectric material has a lower dielectric constant than the high-k film.
5. The method of claim 1 , further comprising:
prior to selectively depositing the high-k film, exposing the substrate to an isotropic oxidizing plasma that forms an oxide layer on the nanowires.
6. The method of claim 5 , further comprising:
removing the oxide layer from the nanowires.
7. The method of claim 1 , wherein the nanowires consist of Si, SiGe, or both Si and SiGe.
8. The method of claim 1 , wherein the vertical spacers contain a SiCOH material, a dielectric material with a dielectric constant less than about 7 , or airgap spacers.
9. The method of claim 1 , wherein the high-k film includes HfO 2 , ZrO 2 , TiO 2 , or Al 2 O 3 .
10. The method of claim 1 , wherein the nanowires consist of Si and the metal-containing gate electrode layer contains TiSiN, TiA 1 C, Ti-rich TiN, W, WN x , Mo, or Pt.
11. The method of claim 1 , wherein the nanowires consist of SiGe and the metal-containing gate electrode layer contains TiN, TiON, Ru, W, WN x , Mo, or Pt.
12. The method of claim 1 , further comprising depositing a dielectric threshold voltage adjustment layer on the high-k film.
13. The method of claim 12 , wherein the nanowires consist of Si and the dielectric threshold voltage adjustment layer includes La 2 O 3 or Y 2 O 3 .
14. The method of claim 12 , wherein the nanowires consist of SiGe and the dielectric threshold voltage adjustment layer includes Al 2 O 3 .
15. The method of claim 1 , further comprising exposing the high-k film to an isotropic oxidizing plasma that forms an oxide layer at an interface of the nanowires and the high-k film.
16. The method of claim 1 , wherein the selective depositing the high-k film includes blocking the high-k film deposition on the vertical spacers.
17. The method of claim 16 , wherein the blocking includes forming self-assembled monolayers (SAMs) on the vertical spacers.
18. The method of claim 1 , wherein the selective depositing the metal-containing gate electrode layer includes blocking the metal-containing gate electrode layer deposition on the vertical spacers.
19. The method of claim 18 , wherein the blocking includes forming self-assembled monolayers (SAMs) on the vertical spacers.
20. A method of forming a nanowire device, the method comprising:
providing a substrate containing Si, SiGe, or both Si and SiGe nanowires between vertical spacers;
selectively depositing a dielectric material on the vertical spacers, wherein the selectively depositing the dielectric material on the vertical spacers includes depositing sufficient dielectric material to reduce gate-to-drain capacitance in the nanowire device;
selectively depositing a high-k film on the nanowires relative to the vertical spacers by blocking the high-k film deposition on the vertical spacers, wherein the dielectric material has a lower dielectric constant than the high-k film; and
selectively depositing a metal-containing gate electrode layer on the high-k film relative to the vertical spacers by blocking the metal-containing gate electrode layer deposition on the vertical spacers.