Resistive Memory Cell With Sloped Bottom Electrode

Abstract

A method of forming a resistive memory cell, e.g., a CBRAM or ReRAM cell, may include forming a plurality of bottom electrode connections, depositing a bottom electrode layer over the bottom electrode connections, performing an etch to remove portions of the bottom electrode layer to form at least one upwardly-pointing bottom electrode region above the bottom electrode connections, each upwardly-pointing bottom electrode region defining a bottom electrode tip, and forming an electrolyte region and a top electrode over each bottom electrode tip such that the electrolyte region is arranged between the top electrode and the respective bottom electrode top.

1 - 13 . (canceled) 
     
     
         14 . A resistive memory cell, comprising:
 a plurality of bottom electrode connections;   at least one bottom electrode region formed over and conductively coupled to the bottom electrode connections, each bottom electrode region having at least two sloped sidewalls and defining an upwardly-pointing tip;   an electrolyte region and a top electrode over each bottom electrode tip such that the electrolyte region is arranged between the top electrode and the respective bottom electrode top; and   a top electrode connection conductively coupled to each top electrode.   
     
     
         15 . The resistive memory cell of  claim 14 , wherein each bottom electrode region extends over and is conductively coupled to multiple bottom electrode connections. 
     
     
         16 . The resistive memory cell of  claim 14 , wherein each bottom electrode region is aligned with and conductively coupled to a single bottom electrode connection. 
     
     
         17 . The resistive memory cell of  claim 14 , wherein each upwardly-pointing bottom electrode region is an elongated region having a pair of sloped sidewalls that meet at a pointed tip edge and define a triangular cross-sectional shape. 
     
     
         18 . The resistive memory cell of  claim 14 , wherein each upwardly-pointing bottom electrode region comprises a pyramid shape. 
     
     
         19 . The resistive memory cell of  claim 14 , wherein each pyramid shaped bottom electrode region has three sloped sidewalls. 
     
     
         20 . The resistive memory cell of  claim 14 , wherein each pyramid shaped bottom electrode region has four sloped sidewalls. 
     
     
         21 . A resistive memory cell, comprising:
 a plurality of bottom electrode connections electrically separated from each other within a substrate;   a bottom electrode layer over the bottom electrode connections and substrate;   wherein portions of the bottom electrode layer are removed to form a plurality of bottom electrodes, each bottom electrode having first and second sidewalls forming at least one upwardly-pointing bottom electrode region above the bottom electrode connections, each upwardly-pointing bottom electrode region defining a bottom electrode tip;   an electrolyte layer deposited directly on the plurality of bottom electrodes and the substrate wherein said electrolyte layer is patterned such that an electrolyte region is formed directly on each bottom electrode tip and directly on its associated first and second sidewall; and   a top electrode over said electrolyte region.   
     
     
         22 . The resistive memory cell of  claim 21 , wherein the electrolyte region formed on each bottom electrode tip is configured to provide a path for the formation of a conductive filament or vacancy chain from the bottom electrode tip to the respective top electrode, via the electrolyte region, when a voltage bias is applied to the resistive memory cell. 
     
     
         23 . The resistive memory cell of  claim 21 , wherein the resistive memory cell is a conductive bridging memory (CBRAM) cell. 
     
     
         24 . The resistive memory cell of  claim 21 , wherein the resistive memory cell is a resistive RAM (ReRAM) cell. 
     
     
         25 . The resistive memory cell of  claim 21 , wherein:
 the at least one upwardly-pointing bottom electrode region comprises at least one elongated bottom electrode region that extends over and is conductively connected to multiple bottom electrode connections.   
     
     
         26 . The resistive memory cell of  claim 25 , wherein said first and second sidewalls are a pair of sloped sidewalls that meet at a pointed tip edge and define a triangular cross-sectional shape. 
     
     
         27 . The resistive memory cell of  claim 21 , wherein each upwardly-pointing bottom electrode region is pyramid shaped. 
     
     
         28 . The resistive memory cell of  claim 27 , wherein each pyramid shaped bottom electrode region has three sloped sidewalls. 
     
     
         29 . The resistive memory cell of  claim 27 , wherein each pyramid shaped bottom electrode region has four sloped sidewalls. 
     
     
         30 . The resistive memory cell of  claim 21 , wherein each upwardly-pointing bottom electrode region is aligned with and conductively connected to a single bottom electrode connection. 
     
     
         31 . The resistive memory cell of  claim 21 , comprising a two-dimensional array of bottom electrode connections; and
 a two-dimensional array of pyramid shaped bottom electrode regions, each conductively coupled to one of the bottom electrode connections.   
     
     
         32 . The resistive memory cell of  claim 31 , comprising a plurality of elongated electrolyte regions and corresponding elongated top electrodes, each elongated electrolyte region and corresponding elongated top electrode covering a row of multiple pyramid shaped bottom electrode regions.