Storage device

Abstract

The object of the invention is to avoid an unselected data line being driven in a memory array composed of memory cells each of which uses a storage element depending upon variable resistance and a selection transistor when the selection transistors in all memory cells on a selected word line conduct. To achieve the object, a source line parallel to a data line is provided, a precharge circuit for equipotentially driving both and a circuit for selectively driving the source line are arranged. Owing to this configuration, a current path is created in only a cell selected by a row decoder and a column decoder and a read-out signal can be generated. Therefore, a lower-power, lower-noise and more highly integrated nonvolatile memory such as a phase change memory can be realized, compared with a conventional type.

1 . A storage device comprising:
 a first metal wiring;   a second metal wiring provided over the first metal wiring; and   a memory cell coupled between the first metal wiring and the second metal wiring, and having a storage element and a selection transistor the selection transistor being coupled to the storage element in series and having a channel region made of a poly-silicon and a gate electrode,   wherein a resistance value of the storage element varies by a current flowing in the storage element,   wherein the current flowing in the storage element is controlled by a voltage of the gate electrode of the selection element.   
     
     
         2 . A storage device according to  claim 1 ,
 wherein the gate electrode of the selection element is provided at the side of the channel region of the selection element.   
     
     
         3 . A storage device according to  claim 1 ,
 wherein the selection element has two diffusion layer regions that function as source and drain region of the selection elements.   
     
     
         4 . A storage device according to  claim 3 ,
 wherein the storage element is provided on the selection element.   
     
     
         5 . A storage device according to  claim 1 , further comprising:
 a first transistor provided on the substrate,   wherein the first metal wiring is coupled to the first transistor.