RRAM retention by depositing Ti capping layer before HK HfO
First Claim
1. A resistance random access memory (RRAM) device comprising:
- a variable resistance dielectric layer having a top surface and a bottom surface;
a cathode disposed over the variable resistance dielectric layer and abutting the top surface;
a metal capping layer disposed below the variable resistance dielectric layer and abutting the bottom surface; and
an anode disposed below the metal capping layer at a location vertically between the metal capping layer and a semiconductor body, wherein the anode comprises a bump protruding outward from a lower surface of the anode that faces away from the metal capping layer.
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Abstract
The present disclosure relates to a resistance random access memory (RRAM) device architecture where a Ti metal capping layer is deposited before the deposition of the HK HfO resistance switching layer. Here, the capping layer is below the HK HfO layer, and hence no damage will occur during the top RRAM electrode etching. The outer sidewalls of the capping layer are substantially aligned with the sidewalls of the HfO layer and hence any damage that may occur during future etching steps will happen at the outer side walls of the capping layer that are positioned away from the oxygen vacancy filament (conductive filament) in the HK HfO layer. Thus the architecture in the present disclosure, improves data retention.
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Citations
19 Claims
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1. A resistance random access memory (RRAM) device comprising:
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a variable resistance dielectric layer having a top surface and a bottom surface; a cathode disposed over the variable resistance dielectric layer and abutting the top surface; a metal capping layer disposed below the variable resistance dielectric layer and abutting the bottom surface; and an anode disposed below the metal capping layer at a location vertically between the metal capping layer and a semiconductor body, wherein the anode comprises a bump protruding outward from a lower surface of the anode that faces away from the metal capping layer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 17, 18)
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11. A resistance random access memory (RRAM) stack of an RRAM device comprising:
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a bottom electrode comprising TaN; a Ti (titanium) metal capping layer arranged over the bottom electrode; a HK-HfO (high-k hafnium oxide) variable resistance dielectric layer arranged over the Ti metal capping layer; a top electrode comprising a TaN (tantalum nitride) layer over a TiN (titanium nitride) layer; a pair of sidewall spacers arranged laterally about outer sidewalls of the top electrode, wherein the top electrode has a first width as measured between its outer sidewalls; and wherein the HK-HfO variable resistance dielectric layer and the Ti metal capping layer each have a second width as measured between their respective outer sidewalls, wherein the second width is greater than the first width. - View Dependent Claims (12)
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13. A method of forming a resistance random-access memory (RRAM) stack comprising:
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providing a semiconductor base surface comprising a metal interconnect structure disposed within a low-k dielectric layer; forming a dielectric protection layer having an opening that extends from an upper surface of the dielectric protection layer to the metal interconnect structure; depositing an anode layer above the dielectric protection layer, the anode layer touching the metal interconnect structure through the opening in the dielectric protection layer; depositing a metal capping layer above the anode layer, wherein the metal capping layer is vertically separated from a semiconductor body by the anode layer; depositing a variable resistance dielectric layer above the metal capping; and depositing a cathode layer above the variable resistance dielectric layer. - View Dependent Claims (14, 15, 16, 19)
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Specification