Non-volatile storage with metal oxide switching element and methods for fabricating the same
Non-volatile storage elements having a reversible resistivity-switching element and techniques for fabricating the same are disclosed herein. The reversible resistivity-switching element may be formed by depositing an oxygen diffusion resistant material (e.g., heavily doped Si, W, WN) over the top electrode. A trap passivation material (e.g., fluorine, nitrogen, hydrogen, deuterium) may be incorporated into one or more of the bottom electrode, a metal oxide region, or the top electrode of the reversible resistivity-switching element. One embodiment includes a reversible resistivity-switching element having a bi-layer capping layer between the metal oxide and the top electrode. Fabricating the device may include depositing (un-reacted) titanium and depositing titanium oxide in situ without air break. One embodiment includes incorporating titanium into the metal oxide of the reversible resistivity-switching element. The titanium might be implanted into the metal oxide while depositing the metal oxide, or after deposition of the metal oxide.
1. A method for fabricating a resistive random access memory element, the method comprising:
forming a bottom electrode;
forming a metal oxide region above the bottom electrode; and
forming a top electrode including:
depositing an electrically conductive region above the metal oxide region, the electrically conductive region having an exposed surface; and
depositing an electrically conductive oxygen diffusion resistant region on the exposed surface of the electrically conductive region to prevent formation of an oxide layer on the surface of the electrically conductive region, wherein the forming a bottom electrode and the forming a top electrode includes implanting a trap passivation material into one or more of the bottom electrode or the top electrode.
2. A method as recited in claim 1 , wherein the depositing an oxygen diffusion resistant region above the electrically conductive region includes depositing an oxygen diffusion resistant region in contact with the electrically conductive region.
3. A method as recited in claim 1 , wherein the depositing an oxygen diffusion resistant region includes depositing heavily doped silicon, tungsten, or tungsten nitride.
4. A method as recited in claim 1 , wherein the depositing an oxygen diffusion resistant region includes depositing the oxygen diffusion resistant region in situ without air break.
5. A method as recited in claim 1 , wherein forming the metal oxide region includes depositing a region of hafnium oxide.
6. A method as recited in claim 1 , wherein depositing the electrically conductive region includes depositing doped silicon.
7. A method as recited in claim 1 , wherein depositing the electrically conductive region includes depositing a metal.
8. A method as recited in claim 1 , wherein the forming a bottom electrode includes depositing doped silicon.
9. A method as recited in claim 1 , further comprising forming a capping layer between the metal oxide region and the electrically conductive region.
10. The method of claim 1 , wherein the oxygen diffusion resistant region includes heavily doped silicon.
11. The method of claim 1 , wherein the oxygen diffusion resistant region includes tungsten nitride.