Resistive Switching Element and Use Thereof

Abstract

A bipolar resistive switching device including an electrically conductive bottom electrode, a stack of transition metal oxides layers, a number of transition metal oxide layers being equal or greater than 2, the stack including: at least one MOx layer, at least one oxygen gettering layer NOy, wherein the resistive switching device further includes an electrically conductive top electrode.

1 - 6  (canceled) 
     
     
         7 . A process for manufacturing a bipolar resistive switching device comprising steps of:
 creating a bottom electrode from an electrically conductive material;   creating a top electrode from an electrically conductive material; and   creating a stack of transition metal oxide layers sandwiched in between the top electrode and the bottom electrode, a number of transition metal oxide layers being equal or greater than 2, the stack comprising at least one MO x  layer, and at least one oxygen gettering layer NO N .   
     
     
         8 . The process of  claim 7  wherein the oxygen gettering layer comprises a transition metal oxide NO N , wherein the metal N includes at least one member of a group consisting of: Cr, Ti, Hf, and Nb. 
     
     
         9 . The process of  claim 7 , wherein the metal M includes at least one member of a group consisting of: Cr, Ti, Hf, Ta, and Nb. 
     
     
         10 . The process of  claim 7 , further comprising a step of:
 creating at least one layer of metal to be included in the stack of transition metal oxide layers.   
     
     
         11 . The process of  claim 7 , wherein
 the step of creating the electrically conductive bottom electrode includes starting from an electrically insulated Si substrate, and depositing the bottom electrode (BE) lines with a lift-off method,   the step of creating the stack of metal oxide layers includes,   depositing the MO x  layer by means of sputtering from a MO z  target, values of the stochiometric number z are in the range 0≦z≦2.5, and   evaporating a metallic N layer to form the oxygen gettering NO y  layer at the interface between N and TaO x , and   the step of creating the electrically conductive top electrode includes starting from the metal oxide layer, and depositing the top electrode lines with a lift-off method.   
     
     
         12 . The process of  claim 7  wherein a value of the stochiometric number y is in the range 0<y≦2. 
     
     
         13 . The process of  claim 7 , wherein values of the stochiometric number x are in the range 0<x≦2.5. 
     
     
         14 . The process of  claim 7  for which the electrically conductive electrodes in the steps of creating the bottom electrode, and creating the top electrode, and the metal oxide layers in the step of creating the metal oxide layers stack, are obtained by deposition steps which correspond to at least one of the following:
 sputtering deposition; 
 evaporation method; and 
 atomic layer deposition. 
 
     
     
         15 . The process of  claim 7 , wherein
 the step of creating the stack of metal oxide layers comprises:   depositing the MO x  layer by sputtering from a MO z  target, values of the stochiometric number z are in the range of 0≦z≦2.5, and   evaporating a metallic N layer to form the oxygen gettering NO y  layer at the interface between N and TaO x , and   the step of creating the electrically conductive top electrode includes starting from the metal oxide layer, and depositing the top electrode lines with a lift-off method.   
     
     
         16 . The process of  claim 15 , wherein the step of creating the electrically conductive bottom electrode comprises:
 depositing bottom electrode lines starting from a CMOS circuit.   
     
     
         17 . The process of  claim 15 , wherein the step of creating the electrically conductive bottom electrode comprises:
 starting from a CMOS circuit, the CMOS circuit including conductive electrode lines which are used as the electrically conductive bottom electrode.   
     
     
         18 . The process of  claim 15 , wherein the step of creating the electrically conductive bottom electrode comprises:
 depositing bottom electrode lines starting from an electrically insulated Si substrate.   
     
     
         19 . The process of  claim 15 , wherein the step of creating the electrically conductive bottom electrode comprises:
 starting from an electrically insulated Si substrate, the electrically insulated Si substrate including conductive electrode lines which are used as the electrically conductive bottom electrode.   
     
     
         20 . (canceled) 
     
     
         21 . A multiplexer circuit comprising:
 a plurality of bipolar resistive switching devices and transistors, wherein the bipolar resistive switching devices serve as routing switching, and wherein transistors are configured to program the multiplexer circuit.   
     
     
         22 . A read/write circuit comprising:
 a digital controller that has a digital state machine configured to control write operation according to a protocol;   an analog read circuitry including,
 a high gain differential amplifier, 
 a current comparator, 
 a current calibration circuitry designed for a column, 
 a high gain operational amplifier, 
 a voltage comparator, and 
 a voltage calibration circuitry; 
   a further analog read circuitry to set each un-selected row voltage to a same voltage level as the column voltage levels;   a reference voltage generation block controlled by the digital controller to keep the row and column voltage levels at sufficient voltage levels in order to program a Resistive Switching Material element contents with minimum current consumption; and   column and row decoders controlled by the digital controller to select an appropriate voltage level on the selected row and selected column.   
     
     
         23 . The read/write circuit of  claim 22 ,
 wherein a sequence of write operations is applied and verified by a sequence of read operations to ensure that a specific resistive switching material stores a specific resistance state.   
     
     
         24 . (canceled)