Lithographic memristive array

Abstract

A memristive device is described. The memristive device includes a first layer having a first plurality of conductive lines, a second layer having a second plurality of conductive lines, and memristive interlayer connectors. The first and second layers differ. The first and second pluralities of conductive lines are each lithographically defined. The first and second pluralities of conductive lines are insulated from each other. The memristive interlayer connectors are memristively coupled with a first portion of the first plurality of conductive lines and memristively coupled with a second portion of the second plurality of conductive lines. The memristive interlayer connectors are thus sparsely coupled with the first and second pluralities of conductive lines. Each memristive interlayer connector includes a conductive portion and a memristive portion. The memristive portion is between the conductive portion and corresponding line(s) of the first plurality of conductive lines and/or the second plurality of conductive lines.

What is claimed is: 
     
         1 . A memristive device, comprising:
 a first layer including a first plurality of conductive lines, the first plurality of conductive lines being lithographically defined;   a second layer including a second plurality of conductive lines, the second layer being different from the first layer, the second plurality of conductive lines being insulated from the first plurality of conductive lines, the second plurality of conductive lines being lithographically defined; and   a plurality of memristive interlayer connectors being memristively coupled with a first portion of the first plurality of conductive lines and memristively coupled with a second portion of the second plurality of conductive lines such that the plurality of memristive interlayer connectors are sparsely coupled with the first plurality of conductive lines and sparsely coupled with the second plurality of conductive lines, each of the plurality of memristive interlayer connectors including a conductive portion and a memristive portion, the memristive portion residing between the conductive portion and at least one corresponding line of at least one of the first plurality of conductive lines or of the second plurality of conductive lines.   
     
     
         2 . The memristive device of  claim 1 , wherein the first plurality of conductive lines have a first long axis oriented in a first direction, the second plurality of conductive lines have a second long axis oriented in a second direction, the first direction being at a nonzero acute angle from the second direction. 
     
     
         3 . The memristive device of  claim 1 , wherein each conductive line of the at least one of the first plurality of conductive lines and the second plurality of conductive lines includes a plurality of line segments having a plurality of long axes oriented in a plurality of directions. 
     
     
         4 . The memristive device of  claim 1 , wherein each conductive line of at least one of the first plurality of conductive lines and the second plurality of conductive lines includes non-linear sections, forming at least one irregular network. 
     
     
         5 . The memristive device of  claim 1 , wherein the first plurality of conductive lines has a first connectivity, the second plurality of conductive lines has a second connectivity and the memristive device has a third connectivity less than the first connectivity and less than the second connectivity. 
     
     
         6 . The memristive device of  claim 1 , further comprising:
 a plurality of conductive interlayer connectors corresponding to the plurality of memristive interlayer connectors, the plurality of conductive interlayer connectors being electrically connected to a third portion of the first plurality of conductive lines and being electrically connected to a fourth portion of the second plurality of conductive lines.   
     
     
         7 . The memristive device of  claim 6 , further comprising:
 a plurality of input neurons coupled to at least a portion of the plurality of conductive interlayer connectors; and   a plurality of output neurons coupled to at least a portion of the plurality of memristive interlayer connectors.   
     
     
         8 . The memristive device of  claim 6 , wherein at least one of the third portion of the first plurality of conductive lines and the fourth portion of the second plurality of conductive lines include a plurality of clusters. 
     
     
         9 . The memristive device of  claim 1 , wherein at least one of the first plurality of conductive lines and the second plurality of conductive lines are electrically floating. 
     
     
         10 . The memristive device of  claim 1 , wherein the conductive portion is a conductive pillar having a sidewall; and
 wherein the memristive portion surrounds at least a portion of the sidewall.   
     
     
         11 . The memristive device of  claim 1 , wherein each of at least one of the first portion of the first plurality of conductive lines and the second portion of the second plurality of conductive lines is coupled to the plurality of memristive interlayer connectors by a conductive branch structure. 
     
     
         12 . The memristive device of  claim 11 , wherein the memristive portion of each of the plurality of memristive interlayer connectors includes a memristive layer in proximity to the conductive branch structure. 
     
     
         13 . A neural network, comprising:
 a first layer including a first plurality of conductive lines, the first plurality of conductive lines being lithographically defined;   a second layer including a second plurality of conductive lines, the second layer being different from the first layer, the second plurality of conductive lines being insulated from the first plurality of conductive lines, the second plurality of conductive lines being lithographically defined;   a plurality of memristive interlayer connectors being memristively coupled with a first portion of the first plurality of conductive lines and memristively coupled with a second portion of the second plurality of conductive lines such that the plurality of memristive interlayer connectors are sparsely coupled with the first plurality of conductive lines and sparsely coupled with the second plurality of conductive lines, each of the plurality of memristive interlayer connectors including a conductive portion and a memristive portion, the memristive portion residing between the conductive portion and at least one corresponding line of at least one of the first plurality of conductive lines or of the second plurality of conductive lines; and   a plurality of neurons coupled to the plurality of memristive interlayer connectors.   
     
     
         14 . A method, comprising:
 lithographically defining a first plurality of conductive lines in a first layer;   lithographically defining a second plurality of conductive lines in a second layer, the second layer being different from the first layer, the second plurality of conductive lines being insulated from the first plurality of conductive lines; and   providing a plurality of memristive interlayer connectors coupled with a first portion of the first plurality of conductive lines and coupled with a second portion of the second plurality of conductive lines such that the plurality of memristive interlayer connectors are sparsely coupled with the first plurality of conductive lines and sparsely coupled with the second plurality of conductive lines, each of the plurality of memristive interlayer connectors including a conductive portion and a memristive portion, the memristive portion residing between the conductive portion and at least one corresponding line of at least one of the first plurality of conductive lines or of the second plurality of conductive lines.   
     
     
         15 . The method of  claim 14 , wherein the lithographically defining the first plurality of conductive lines further includes:
 defining a first long axis oriented in a first direction for the first plurality of conductive lines; and   wherein the lithographically defining the second plurality of conductive lines further includes defining a second long axis oriented in a second direction, the first direction being at a nonzero acute angle from the second direction.   
     
     
         16 . The method of  claim 14 , wherein each conductive line of at least one of the first plurality of conductive lines and the second plurality of conductive lines includes a plurality of line segments having a plurality of long axes oriented in a plurality of directions. 
     
     
         17 . The method of  claim 14 , further comprising:
 providing a plurality of conductive interlayer connectors corresponding to the plurality of memristive interlayer connectors, the plurality of conductive interlayer connectors being electrically connected to a third portion of the first plurality of conductive lines and being electrically connected to a fourth portion of the second plurality of conductive lines.   
     
     
         18 . The method of  claim 17 , further comprising:
 providing a plurality of input neurons coupled to at least a portion of the plurality of conductive interlayer connectors; and   providing a plurality of output neurons coupled to at least a portion of the plurality of memristive interlayer connectors.   
     
     
         19 . The method of  claim 18 , wherein at least one of the third portion of the first plurality of conductive lines and the fourth portion of the second plurality of conductive lines include a plurality of clusters. 
     
     
         20 . The method of  claim 14 , wherein at least one of the first plurality of conductive lines and the second plurality of conductive lines are electrically floating.