Variable resistance material layers and variable resistance memory devices including the same

Abstract

A variable resistance material layer including germanium (Ge), antimony (Sb), tellurium (Te), and at least one type of impurities X. The variable resistance material layer having a composition represented by a chemical formula of X p (Ge a Sb (1-a-b) Te b ) (1-p) , wherein an atomic concentration of the impurities X is in a range of 0<p≦0.2, an atomic concentration of Ge is in a range of 0.05≦a<0.19, and an atomic concentration of Te is in a range of 0.42≦b≦0.56.

1 .- 12 . (canceled) 
     
     
         13 . A variable resistance material layer having a composition defined by a region surrounded by first, second, third and fourth composition lines in a ternary phase diagram of germanium (Ge), antimony (Sb), and tellurium (Te), the variable resistance material layer comprising:
 at least one type of impurities,   wherein the first composition line connects compositions having an atomic concentration of Te of about 0.42,   the second composition line connects compositions having an atomic concentration of Te of about 0.56,   the third composition line connects compositions having an atomic concentration of Ge of about 0.05,   and the fourth composition line connects compositions having an atomic concentration of Ge of about 0.19.   
     
     
         14 .- 20 . (canceled) 
     
     
         21 . A variable resistance material layer, comprising germanium (Ge), antimony (Sb), tellurium (Te), and at least one impurity,
 wherein the at least one impurity is present in the variable resistance material layer in an atomic percent of 20% or less,   Ge is present in the variable resistance material layer in an atomic percent of greater than or equal to 5% and less than 19%, and   Te is present in the variable resistance material layer in an atomic percent of greater than or equal to 42% and less than or equal to 56%.   
     
     
         22 . The variable resistance material layer of  claim 21 , wherein a total atomic percent of impurities present in the variable resistance material layer is 20% or less. 
     
     
         23 . The variable resistance material layer of  claim 22 , wherein the impurities are selected from the group consisting of boron (B), carbon (C), nitrogen (N), oxygen (O), aluminum (Al), silicon (Si), phosphorous (P), sulfur (S), bismuth (Bi), and any combination thereof. 
     
     
         24 . The variable resistance material layer of  claim 21 , wherein the variable resistance material layer has a composition represented by a chemical formula of
   X p Y q (Ge a Sb (1-a-b) Te b ) (1-p-q) ,   wherein X and Y represent different types of impurities and q may be 0,   and wherein a sum of atomic concentrations of X and Y is in a range of 0<p+q≦0.2,   an atomic concentration of Ge is in a range of 0.05≦a≦0.19, and   an atomic concentration of Te is in a range of 0.42≦b≦0.56.   
     
     
         25 . The variable resistance material layer of  claim 21 , wherein the variable resistance material layer has a reset current equal to or less than about 200 μA. 
     
     
         26 . The variable resistance material layer of  claim 21 , wherein the variable resistance material layer has a crystallization rate of less than about 80 ns. 
     
     
         27 . The variable resistance material layer of  claim 21 , wherein the variable resistance material layer is kept in an amorphous state for at least one year at a temperature equal to or less than about 70° C. 
     
     
         28 . A variable resistance material layer pattern, wherein the variable resistance material layer pattern is formed from the variable resistance material layer of  claim 21 . 
     
     
         29 . The variable resistance material layer pattern of  claim 28 ,
 wherein the variable resistance material layer pattern has a composition represented by a chemical formula of
   X p Y q (Ge a Sb (1-a-b) Te b ) (1-p-q) , 
   wherein X and Y represent different types of impurities and q may be 0,   and wherein a sum of atomic concentrations of X and Y is in a range of 0<p+q≦0.2,   an atomic concentration of Ge is in a range of 0.05≦a<0.19, and   an atomic concentration of Te is in a range of 0.42≦b≦0.56.   
     
     
         30 . (canceled)