ReRAM stacks preparation by using single ALD or PVD chamber
View Patent ↗Systems and methods for preparing resistive switching memory devices such as resistive random access memory (ReRAM) devices wherein both oxide and nitride layers are deposited in a single chamber are provided. Various oxide and nitride based layers in the ReRAM device such as the switching layer, current-limiting layer, and the top electrode (and optionally the bottom electrode) are deposited in the single chamber. By fabricating the ReRAM device in a single chamber, throughput is increased and cost is decreased. Moreover, processing in a single chamber reduces device exposure to air and to particulates, thereby minimizing device defects.
1. A method of making a resistive switching memory device on a substrate, the method comprising:
fabricating the resistive switching memory device in a single chamber, wherein the fabricating comprises:
forming a first layer above the substrate, the first layer operable as a first electrode of the resistive switching memory device;
forming a second layer above the first layer, the second layer operable as a resistive switching layer of the resistive switching memory device;
forming a third layer above the second layer, the third layer operable as a current limiting layer of the resistive switching memory device; and
forming a fourth layer above the third layer, the fourth layer operable as a second electrode of the resistive switching memory device,
wherein the first layer and the fourth layer are formed from different materials; and
wherein the second layer, the third layer, and the fourth layer are formed under a same range of substrate temperature range process conditions, chamber pressure range process conditions, and carrier gas purge range process conditions.
2. The method of claim 1 , wherein the first layer, the second layer, the third layer, and the fourth layer are deposited by atomic layer deposition.
3. The method of claim 1 , wherein the second layer comprises one or more metal oxides.
4. The method of claim 3 , wherein the one or more metal oxides comprise one or more of hafnium oxide (HfxOy), tantalum oxide (TaxOy), aluminum oxide (AlxOy), lanthanum oxide (LaxOy), yttrium oxide (YxOy), dysprosium oxide (DyxOy), ytterbium oxide (YbxOy), zirconium oxide (ZrxOy), titanium oxide (TiOx), nickel oxide (NiOx), zinc oxide (ZnxOy), or combinations thereof
5. The method of claim 1 , wherein the third layer comprises one or more metal nitrides.
6. The method of claim 5 , wherein the one or more metal nitrides comprises hafnium nitride (HfxNy), tantalum nitride (TaxNy), titanium aluminum nitride (TixAlyNz), titanium nitride (TixNy), or combinations thereof.
7. The method of claim 1 , wherein the first layer comprises polysilicon.
8. The method of claim 1 , wherein the fourth layer comprises titanium nitride.
9. The method of claim 1 , wherein the second layer comprises one of hafnium oxide (HfxOy), tantalum oxide (TaxOy), aluminum oxide (AlxOy), lanthanum oxide (LaxOy), yttrium oxide (YxOy), dysprosium oxide (DyxOy), ytterbium oxide (YbxOy), zirconium oxide (ZrxOy), titanium oxide (TiOx), nickel oxide (NiOx), zinc oxide (ZnxOy), or a combination thereof.
10. The method of claim 1 , wherein the third layer comprises one of hafnium nitride (HfxNy), tantalum nitride (TaxNy), titanium aluminum nitride (TixAlyNz), titanium nitride (TixNy), or a combination thereof.
11. The method of claim 1 , wherein the second layer comprises a metal oxide and wherein the third layer comprises a metal nitride.
12. The method of claim 11 , wherein the forming of the second layer comprises supplying a first chemical precursor, wherein the forming of the third layer comprises supplying a second chemical precursor, and wherein the first chemical precursor and the second chemical precursor comprise a same ligand.
13. The method of claim 1 , wherein the forming of the second layer comprises supplying one of TDMAHf, TEMAHf, HfCl4, TDMATi, TEMATi, TiCl4, TMA, TEMAZr, or PDMATa into the single chamber while the substrate is maintained at a temperature of between 200° C. and 350° C. followed by supplying one of H2O, O3, or plasma O2 into the single chamber.
14. The method of claim 13 , wherein the forming of the third layer comprises supplying TDMAHf, TEMAHf, HfCl4, TDMATi, TEMATi, TiCl4, or PDMATa into the single chamber followed by supplying one of NH3 or H2 into the single chamber.
15. The method of claim 14 , wherein the forming of the fourth layer comprises supplying TDMAHf, TEMAHf, HfCl4, TDMATi, TEMATi, TiCl4, or PDMATa followed by supplying one of NH3 or H2 into the single chamber.
16. The method of claim 1 , wherein the second layer comprises hafnium oxide and wherein the third layer comprises titanium aluminum nitride.
17. The method of claim 1 , wherein the resistive switching layer is configured to change a resistance between a low resistance state and a high resistance state.
18. The method of claim 1 , wherein the second layer and the third layer are formed in a same processing chamber.