Sidewall-Type Memory Cell

Abstract

A sidewall-type memory cell (e.g., a CBRAM, ReRAM, or PCM cell) may include a bottom electrode, a top electrode layer defining a sidewall, and an electrolyte layer arranged between the bottom and top electrode layers, such that a conductive path is defined between the bottom electrode and a the top electrode sidewall via the electrolyte layer, wherein the bottom electrode layer extends generally horizontally with respect to a horizontal substrate, and the top electrode sidewall extends non-horizontally with respect to the horizontal substrate, such that when a positive bias-voltage is applied to the cell, a conductive path grows in a non-vertical direction (e.g., a generally horizontal direction or other non-vertical direction) between the bottom electrode and the top electrode sidewall.

1 - 24 . (canceled) 
     
     
         25 . A cell for a resistive memory, comprising:
 a bottom electrode extending generally horizontally with respect to a horizontal substrate;   an electrolyte layer formed over the bottom electrode, the electrolyte layer having a non-horizontally extending sidewall region and a horizontally extending upper region;   a top electrode layer extending over the bottom electrode and including (a) a non-horizontally-extending sidewall region formed on the non-horizontally extending sidewall region of the electrolyte layer and (a) a horizontally-extending upper region formed on the horizontally-extending upper region of the electrolyte layer;   wherein the non-horizontally-extending sidewall region includes a laterally outward portion located laterally outwardly from a lateral edge of the bottom electrode;   wherein the respective arrangement of the bottom electrode, electrolyte layer, and top electrode layer define a conductive path between the bottom electrode and the non-horizontally-extending sidewall region of the top electrode layer via the non-horizontally extending sidewall region of the electrolyte layer.   
     
     
         26 . The cell according to  claim 25 , wherein the non-horizontally-extending sidewall region of the top electrode defines a ring shape extending around an outer perimeter of the bottom electrode. 
     
     
         27 . The cell according to  claim 25 , wherein the horizontally-extending upper region of the top electrode layer extends over and parallel to the bottom electrode. 
     
     
         28 . The cell according to  claim 27 , wherein the non-horizontally-extending sidewall region of the electrolyte layer defines a ring extending radially inside the top electrode layer. 
     
     
         29 . The cell according to  claim 25 , wherein the non-horizontally-extending sidewall region of the top electrode has a surface facing the bottom electrode and extending at an angle relative to the horizontal substrate, the angle being between 30 and 90 degrees, non-inclusive. 
     
     
         30 . The cell according to  claim 25 , wherein the non-horizontally-extending sidewall region of the top electrode has a surface facing the bottom electrode and extending at an angle relative to the horizontal substrate, the angle being between 60 and 90 degrees, non-inclusive. 
     
     
         31 . The cell according to  claim 25 , wherein the non-horizontally-extending sidewall region of the top electrode has a surface facing the bottom electrode and extending at an angle relative to the horizontal substrate, the angle being between 45 and 85 degrees, non-inclusive. 
     
     
         32 . The cell according to  claim 25 , wherein the non-horizontally-extending sidewall region of the top electrode has a surface facing the bottom electrode and extending perpendicular to the horizontal substrate. 
     
     
         33 . The cell according to  claim 25 , wherein:
 the bottom electrode layer is formed on a substrate layer and has a bottom electrode layer thickness, and   the top electrode layer is spaced apart from the substrate layer by a distance less than the bottom electrode thickness.   
     
     
         34 . The cell according to  claim 33 , wherein the top electrode layer is spaced apart from the substrate layer by a portion of the electrolyte layer. 
     
     
         35 . The cell according to  claim 33 , wherein a distance between the top electrode layer to the underlying substrate is less than a thickness of the bottom electrode. 
     
     
         36 . A cell for a resistive memory, comprising:
 a bottom electrode formed over a substrate;   a top electrode layer including:
 (a) a non-horizontally-extending sidewall region having a non-horizontal surface facing the bottom electrode, and 
 (b) a horizontally-extending upper region extending over the bottom electrode; and 
   an electrolyte layer located between the bottom electrode and top electrode layer;   wherein at least a portion of the non-horizontally-extending sidewall region of the top electrode is located laterally outwardly from a lateral edge of the bottom electrode; and   wherein the respective arrangement of the bottom electrode, electrolyte layer, and top electrode layer define a conductive path between the bottom electrode and the laterally outward portion of the non-horizontally-extending sidewall region of the top electrode layer via the electrolyte layer.   
     
     
         37 . The cell according to  claim 36 , wherein the electrolyte layer includes:
 (a) a non-horizontally-extending sidewall region having a non-horizontal surface facing the bottom electrode, and   (b) a horizontally-extending upper region having a horizontal surface facing the bottom electrode.   
     
     
         38 . The cell according to  claim 36 , wherein the non-horizontally-extending sidewall region of the top electrode defines a ring shape extending around an outer perimeter of the bottom electrode. 
     
     
         39 . The cell according to  claim 36 , wherein the non-horizontally-extending sidewall region of the top electrode has a surface facing the bottom electrode and extending at an angle relative to a top surface of the substrate, the angle being between 30 and 90 degrees, non-inclusive. 
     
     
         40 . The cell according to  claim 36 , wherein the non-horizontally-extending sidewall region of the top electrode has a surface facing the bottom electrode and extending at an angle relative to a top surface of the substrate, the angle being between 45 and 85 degrees, non-inclusive. 
     
     
         41 . The cell according to  claim 36 , wherein the non-horizontally-extending sidewall region of the top electrode has a surface facing the bottom electrode and extending perpendicular to a top surface of the substrate. 
     
     
         42 . A method, comprising:
 forming a sidewall-type resistive memory cell, the method comprising:
 forming a bottom electrode over a substrate; 
 forming an electrolyte layer over the bottom electrode; and 
 forming a top electrode layer including:
 (a) a non-horizontally-extending sidewall region having a non-horizontal surface adjacent the electrolyte layer and facing the bottom electrode, and 
 (b) a horizontally-extending upper region extending over the bottom electrode; and 
 
 wherein at least a portion of the non-horizontally-extending sidewall region of the top electrode is located laterally outwardly from a lateral edge of the bottom electrode; and 
 wherein the respective arrangement of the bottom electrode, electrolyte layer, and top electrode layer define a conductive path between the bottom electrode and the non-horizontally-extending sidewall region of the top electrode layer via the non-horizontally extending sidewall region of the electrolyte layer. 
   
     
     
         43 . The method according to  claim 42 , wherein the electrolyte layer formed over the bottom electrode includes:
 (a) a non-horizontally-extending sidewall region having a non-horizontal surface facing the bottom electrode, and   (b) a horizontally-extending upper region having a horizontal surface facing the bottom electrode.   
     
     
         44 . The method according to  claim 42 , further comprising applying a positive bias-voltage is applied to the cell such that a conductive path grows in a non-vertical direction between the bottom electrode and the non-horizontally-extending sidewall region of the top electrode.