Method for controlling the forming voltage in resistive random access memory devices
A method of controlling the forming voltage of a dielectric film in a resistive random access memory (ReRAM) device. The method includes depositing a dielectric film contains intrinsic defects on a substrate, forming a plasma-excited treatment gas containing H 2 gas, and exposing the dielectric film to the plasma-excited treatment gas to create additional defects in the dielectric film without substantially changing a physical thickness of the dielectric film, where the additional defects lower the forming voltage needed for generating an electrically conducting filament across the dielectric film. The dielectric film can include a metal oxide film and the plasma-excited treatment gas may be formed using a microwave plasma source.
1. A method of forming a resistive random access memory (ReRAM) device, the method comprising:
depositing a dielectric film directly on a first electrode film, the dielectric film containing intrinsic defects;
forming a plasma-excited treatment gas containing H 2 gas;
exposing the dielectric film to the plasma-excited treatment gas to create additional defects in the dielectric film, wherein the additional defects lower the forming voltage needed for generating an electrically conducting filament across the dielectric film;
thereafter, depositing an additional dielectric film on the dielectric film; and
forming a second electrode film on the additional dielectric film.
2. The method of claim 1 , wherein the exposing the dielectric film to the plasma-excited treatment gas does not substantially change a physical thickness of the dielectric film.
3. The method of claim 1 , wherein the dielectric film includes a metal oxide film selected from the group consisting of HfO 2 , ZrO 2 , TiO 2 , NiO, Al 2 O 3 , Ta 2 O 5 , and laminate films thereof.
4. The method of claim 1 , wherein the additional dielectric film includes a metal oxide film selected from the group consisting of HfO 2 , ZrO 2 , TiO 2 , NiO, Al 2 O 3 , Ta 2 O 5 , and laminate films thereof.
5. The method of claim 1 , wherein the forming a plasma-excited treatment gas includes exciting the treatment gas using a microwave plasma source.
6. The method of claim 1 , wherein the treatment gas consists of H 2 gas, or H 2 gas and Ar gas.
7. The method of claim 1 , wherein a thickness of the dielectric film is about 2 nm and a thickness of the additional dielectric film is about 3 nm.
8. The method of claim 7 , wherein both the dielectric film and the additional dielectric film contain HfO 2 .
9. A method of forming a resistive random access memory (ReRAM) device, the method comprising:
depositing a metal oxide dielectric film directly on first electrode film, the metal oxide dielectric film containing intrinsic defects that include oxygen vacancies;
forming a plasma-excited treatment gas containing H 2 gas, wherein the forming includes exciting the treatment gas using a microwave plasma source;
exposing the metal oxide dielectric film to the plasma-excited treatment gas to create additional defects in the metal oxide dielectric film without substantially changing a physical thickness of the metal oxide dielectric film, wherein the additional defects lower the forming voltage needed for generating an electrically conducting filament across the metal oxide dielectric film;
thereafter, depositing an additional metal oxide dielectric film on the metal oxide dielectric film; and
forming a second electrode film on the additional metal oxide dielectric film.
10. The method of claim 9 , wherein the metal oxide film is selected from the group consisting of HfO 2 , ZrO 2 , TiO 2 , NiO, Al 2 O 3 , Ta 2 O 5 , and laminate films thereof.
11. The method of claim 9 , wherein the additional metal oxide dielectric film is selected from the group consisting of HfO 2 , ZrO 2 , TiO 2 , NiO, Al 2 O 3 , Ta 2 O 5 , and laminate films thereof.
12. The method of claim 9 , wherein the treatment gas consists of H 2 , or H 2 and Ar.
13. The method of claim 9 , wherein a thickness of the metal oxide dielectric film is about 2 nm and a thickness of the additional metal oxide dielectric film is about 3 nm.
14. A resistive random access memory (ReRAM) device, comprising:
a dielectric film in direct contact with a first electrode film, the dielectric film containing intrinsic defects, and additional defects created by exposing the dielectric film to a plasma-excited treatment gas containing H 2 gas, wherein the additional defects lower the forming voltage needed for generating an electrically conducting filament across the dielectric film;
an additional dielectric film on the dielectric film; and
a second electrode film on the additional dielectric film.
15. The device of claim 14 , wherein the dielectric film contains a metal oxide film that is selected from the group consisting of HfO 2 , ZrO 2 , TiO 2 , NiO, Al 2 O 3 , Ta 2 O 5 , and laminate films thereof.
16. The device of claim 14 , wherein the additional dielectric film contains a metal oxide film that is selected from the group consisting of HfO 2 , ZrO 2 , TiO 2 , NiO, Al 2 O 3 , Ta 2 O 5 , and laminate films thereof.
17. The device of claim 14 , wherein the treatment gas consists of H 2 gas, or H 2 gas and Ar gas.
18. The device of claim 14 , wherein the plasma-excited treatment gas is excited using a microwave plasma source.
19. The device of claim 14 , wherein the additional defects in the dielectric film are created without substantially changing a physical thickness of the dielectric film.
20. The device of claim 14 , wherein a thickness of the dielectric film is about 2 nm and a thickness of the additional dielectric film is about 3 nm.