Non-volatile programmable device including phase change layer and fabricating method thereof

Abstract

Provided is a non-volatile programmable device including a first terminal, a first threshold switching layer connected to part of the first terminal, a phase change layer connected to the first threshold switching layer, a second threshold switching layer connected to the phase change layer, a second terminal connected to the second threshold switching layer, and third and fourth terminals respectively connected to a side portion of the phase change layer and the other side portion opposite to the side portion of the phase change layer.

1 . A non-volatile programmable device comprising:
 a first terminal;   a first threshold switching layer connected to the first terminal;   a phase change layer connected to the first threshold switching layer;   a second threshold switching layer connected to the phase change layer;   a second terminal connected to the second threshold switching layer; and   a third terminal and a fourth terminal respectively connected to a side portion of the phase change layer and the other side portion opposite to the side portion of the phase change layer.   
     
     
         2 . The non-volatile programmable device of  claim 1 , wherein the phase change layer is formed of a chalcogenide including one of sulfur (S), selenium (Se), and tellurium (Te), or an antimony compound including antimony (Sb). 
     
     
         3 . The non-volatile programmable device of  claim 1 , wherein the first threshold switching layer or the second threshold switching layer is formed of a chalcogenide that includes one of sulfur (S), selenium (Se), and tellurium (Te), and that further includes arsenic (As) or phosphorus (P). 
     
     
         4 . The non-volatile programmable device of  claim 1 , further comprising a metal-oxide-semiconductor (MOS) transistor having a source/drain terminal connected to the third terminal or the fourth terminal and a gate terminal connected to the second terminal. 
     
     
         5 . A non-volatile programmable device comprising:
 a first terminal;   a first threshold switching layer, a phase change layer, a second threshold switching layer, and a second terminal sequentially formed on the first terminal; and   a third terminal and a fourth terminal respectively connected to a side portion of the phase change layer and the other side portion opposite to the side portion of the phase change layer,   wherein an electrical pulse is supplied to the phase change layer through the first terminal, the first threshold switching layer, the second threshold switching layer, and the second terminal generate a reversible phase change of the phase change layer and control an electric signal that moves through the third terminal, the phase change layer, and the fourth terminal.   
     
     
         6 . The non-volatile programmable device of  claim 5 , wherein the first threshold switching layer and the second threshold switching layer are formed of a threshold switching material. 
     
     
         7 . The non-volatile programmable device of  claim 5 , wherein the phase change layer is formed of a material that changes reversibly between an amorphous state and a crystalline state according to the amount of applied current. 
     
     
         8 . A non-volatile programmable device comprising:
 a first metal layer formed on a semiconductor substrate;   a first threshold switching layer formed on part of the first metal layer;   a second metal layer formed on the first metal layer and the first threshold switching layer, wherein an insulating layer is interposed between the first metal layer and the first threshold switching layer, and the second metal layer;   a phase change layer formed through the second metal layer and the insulating layer, and connected to the first threshold switching layer;   a second threshold switching layer formed on the phase change layer;   a third metal layer that is connected to the first metal layer and to the first threshold switching layer; and   a fourth metal layer formed on the second threshold switching layer,   wherein the third metal layer and the fourth metal layer are first and second terminals connected to the first threshold switching layer and the second threshold switching layer, respectively, and a side portion of the second metal layer and the other side portion opposite to the side portion of the second metal layer are third and fourth terminals which are respectively connected to the phase change layer.   
     
     
         9 . The non-volatile programmable device of  claim 8 , further comprising a metal-oxide-semiconductor (MOS) transistor having a source/drain terminal connected to the third and fourth terminal and a gate terminal connected to the second terminal.