Nonvolatile memory transistor and device including the same

Abstract

Provided are nonvolatile memory transistors and devices including the nonvolatile memory transistors. A nonvolatile memory transistor may include a channel element, a gate electrode corresponding to the channel element, a gate insulation layer between the channel element and the gate electrode, an ionic species moving layer between the gate insulation layer and the gate electrode, and a source and a drain separated from each other with respect to the channel element. A motion of an ionic species at the ionic species moving layer occurs according to a voltage applied to the gate electrode. A threshold voltage changes according to the motion of the ionic species. The nonvolatile memory transistor has a multi-level characteristic.

What is claimed is: 
     
         1 . A neuromorphic device, comprising:
 a synapse device, the synapse device comprising:
 a nonvolatile memory transistor, the nonvolatile memory transistor comprising:
 a channel element; 
 a gate electrode corresponding to the channel element; 
 a gate insulation layer between the channel element and the gate electrode; 
 an ionic species moving layer between the gate insulation layer and the gate electrode; and 
 a source and a drain separated from each other with respect to the channel element, wherein a motion of an ionic species at the ionic species moving layer occurs according to a voltage applied to the gate electrode, wherein a threshold voltage changes according to the motion of the ionic species, and wherein the nonvolatile memory transistor has a multi-level characteristic. 
 
   
     
     
         2 . The neuromorphic device of  claim 1 , further comprising a complementary metal-oxide-semiconductor (CMOS) neuron circuit connected to the synapse device. 
     
     
         3 . The neuromorphic device of  claim 1 , wherein the ionic species moving layer comprises a bipolar memory layer. 
     
     
         4 . The neuromorphic device of  claim 1 , wherein the ionic species moving layer comprises negative ionic species and the threshold voltage increases as a concentration of the negative ionic species in the ionic species moving layer increases in a direction toward the gate insulation layer. 
     
     
         5 . The neuromorphic device of  claim 1 , wherein the nonvolatile memory transistor further comprises a conductive layer between the gate insulation layer and the ionic species moving layer. 
     
     
         6 . The neuromorphic device of  claim 1 , wherein the nonvolatile memory transistor has a multi-level characteristic including at least sixteen levels. 
     
     
         7 . The neuromorphic device of  claim 1 , wherein the ionic species moving layer has a multilayer structure. 
     
     
         8 . The neuromorphic device of  claim 1 , wherein the gate electrode of the nonvolatile memory transistor is connected to a pre-synaptic neuron circuit and the source of the nonvolatile memory transistor is connected to a post-synaptic neuron circuit. 
     
     
         9 . A method of operating a nonvolatile memory transistor, the method comprising:
 moving ionic species in the ionic species moving layer by applying a voltage to the gate electrode; and   turning on the nonvolatile memory transistor.   
     
     
         10 . The method of  claim 9 , wherein, in the moving of the ionic species, the voltage applied to the ionic species moving layer is within a range of about ±5.0 V. 
     
     
         11 . A nonvolatile memory transistor, comprising:
 a source;   a drain;   a gate electrode;   a channel element between the source and the drain; and   an ionic species moving layer between the gate electrode and the channel element, wherein a threshold voltage of the nonvolatile memory transistor changes in response to a movement of ions in the ionic species moving layer.   
     
     
         12 . The nonvolatile memory transistor of  claim 11 , wherein the nonvolatile memory transistor has a multi-level characteristic. 
     
     
         13 . The nonvolatile memory transistor of  claim 11 , wherein the nonvolatile memory transistor has a multi-level characteristic including at least sixteen levels. 
     
     
         14 . The nonvolatile memory transistor of  claim 11 , wherein the ionic species moving layer includes a bipolar memory layer. 
     
     
         15 . The nonvolatile memory transistor of  claim 11 , wherein the ionic species moving layer includes an electrostatic potential that is changed by moving the ionic species according to a voltage applied to the gate electrode. 
     
     
         16 . The nonvolatile memory transistor of  claim 11 , wherein the ionic species includes at least one of oxygen ions or oxygen vacancies. 
     
     
         17 . The nonvolatile memory transistor of  claim 11 , further comprising a gate insulation layer between the ionic species movable layer and the channel element. 
     
     
         18 . The nonvolatile memory transistor of  claim 11 , wherein the ionic species moving layer has a multilayer structure.