Resistive switching memory device architecture for reduced cell damage during processing
View Patent ↗In one embodiment, a resistive switching memory device can include: (i) a plurality of resistive memory cells arranged in a plurality of array blocks, where each resistive memory cell is configured to be programmed to a low resistance state by application of a program voltage in a forward bias direction, and to be erased to a high resistance state by application of an erase voltage in a reverse bias direction; (ii) a plurality of anode plates corresponding to the plurality of array blocks, where each resistive memory cell can include a resistive storage element having an anode coupled to one of the anode plates; (iii) an inactive ring surrounding the plurality of anode plates, where the inactive ring can include a same material as each of the plurality of anode plates; and (iv) a plurality of boundary cells located under the inactive ring.
1. A method of making a resistive switching memory device, the method comprising:
a) forming a plurality of resistive memory cells arranged in a plurality of array blocks, wherein each resistive memory cell is configured to be programmed to a low resistance state by application of a program voltage in a forward bias direction, and to be erased to a high resistance state by application of an erase voltage in a reverse bias direction;
b) forming a plurality of anode plates corresponding to the plurality of array blocks, wherein each resistive memory cell comprises a resistive storage element having an anode coupled to one of the anode plates;
c) forming an inactive ring surrounding the plurality of anode plates, wherein the inactive ring comprises a same material as each of the plurality of anode plates; and
d) forming a plurality of boundary cells located under the inactive ring.
2. The method of claim 1 wherein the same material comprises a metal oxide.
3. The method of claim 1 , wherein the same material comprises an injection barrier layer (IBL).
4. The method of claim 1 , wherein the same material comprises titanium.
5. The method of claim 1 , wherein the same material comprises titanium nitride.
6. The method of claim 1 , wherein each resistive memory cell comprises n+ regions in a p-substrate.
7. The method of claim 6 , wherein each boundary cell comprises p+ regions in the p-substrate.
8. The method of claim 1 , further comprising connecting the inactive ring to a p-substrate of the resistive switching memory device.
9. The method of claim 1 , wherein the forming the plurality of anode plates and the inactive ring comprises:
a) depositing the same material on a surface of the resistive switching memory device;
b) patterning a hard mask layer on the same material to define regions for the plurality of anode plates and the inactive ring; and
c) using plasma etching to remove the same material from areas not covered by the patterned hard mask layer, wherein the plurality of boundary cells are configured to sink current from the plasma etching.
10. The method of claim 1 , wherein the resistive storage element comprises a conductive bridging random-access memory (CBRAM) storage element.