Memory cell, capacitive memory structure, and methods thereof

Abstract

According to various aspects a memory cell is provided, the memory cell including: a first electrode; a second electrode; and a memory layer disposed between the first electrode and the second electrode, wherein the memory layer includes a first memory portion having a first concentration of oxygen vacancies and a second memory portion having a second concentration of oxygen vacancies different from the first concentration of oxygen vacancies.

What is claimed is: 
     
         1 . Memory cell comprising:
 a first electrode;   a second electrode; and   a memory layer disposed between the first electrode and the second electrode,   wherein the memory layer comprises a first memory portion having a first concentration of oxygen vacancies and a second memory portion having a second concentration of oxygen vacancies different from the first concentration of oxygen vacancies.   
     
     
         2 . The memory cell according to  claim 1 ,
 wherein the second concentration of oxygen vacancies is at least 10 times greater than the first concentration of oxygen vacancies.   
     
     
         3 . The memory cell according to  claim 1 ,
 wherein at least one of the first concentration or the second concentration of oxygen vacancies is greater than 10 20  vacancies/cm 3 .   
     
     
         4 . The memory cell according to  claim 1 ,
 wherein the first memory portion comprises or consists of a first material having a first oxygen content, and the second memory portion comprises or consists of a second material having a second oxygen content less than the first oxygen content.   
     
     
         5 . The memory cell according to  claim 4 ,
 wherein the first material comprises oxygen and a metal in a first stoichiometric relationship with one another, and   wherein the second material comprises oxygen and the metal in a second stoichiometric relationship with one another, the first stoichiometric relationship being different from the second stoichiometric relationship.   
     
     
         6 . The memory cell according to  claim 1 ,
 wherein a width of the first memory portion is greater than 5 nm and wherein a thickness of the first memory portion is in the range from about 0.1 nm to about 5 nm, and   wherein a width of the second memory portion is greater than 5 nm a thickness of the second memory portion is in the range from about 0.1 nm to about 5 nm.   
     
     
         7 . The memory cell according to  claim 1 ,
 further comprising a third memory portion having a third concentration of oxygen vacancies, wherein the third concentration of oxygen vacancies is equal to one of the first concentration of oxygen vacancies or the second concentration of oxygen vacancies.   
     
     
         8 . The memory cell according to  claim 7 ,
 further comprising a fourth memory portion having a fourth concentration of oxygen vacancies, wherein the fourth concentration of oxygen vacancies is equal to the other one of the first concentration of oxygen vacancies or the second concentration of oxygen vacancies.   
     
     
         9 . The memory cell according to  claim 1 ,
 wherein the first memory portion comprises a material having a first crystal structure, and the second memory portion comprises a material having a second crystal structure,   wherein the first crystal structure differs from the second crystal structure in a number of oxygen vacancies in the crystal lattice.   
     
     
         10 . The memory cell according to  claim 1 ,
 wherein the memory layer is remanently polarizable or spontaneously polarizable.   
     
     
         11 . The memory cell according to  claim 1 ,
 wherein a material of the first memory portion and/or of the second memory portion comprises at least one of the following materials as a main component:
 hafnium oxide, 
 zirconium oxide, 
 a mixture of hafnium oxide and zirconium oxide. 
   
     
     
         12 . The memory cell according to  claim 1 ,
 wherein the first electrode, the second electrode, and the memory layer form a capacitive memory structure.   
     
     
         13 . The memory cell according to  claim 12 , further comprising:
 a field-effect transistor structure, the field-effect transistor structure comprising a gate structure coupled to the capacitive memory structure, or   wherein the capacitive memory structure is integrated in a field-effect transistor structure.   
     
     
         14 . The memory cell according to  claim 13 ,
 wherein the field-effect transistor structure and the capacitive memory structure are coupled to one another to form a capacitive voltage divider.   
     
     
         15 . The memory cell according to  claim 13 ,
 wherein the gate structure of the field-effect transistor structure comprises a gate electrode and a gate isolation separating the gate electrode from a channel region of the field-effect transistor structure, wherein the gate electrode is coupled to the first electrode of the capacitive memory structure.   
     
     
         16 . Memory cell comprising:
 a first electrode;   a second electrode; and   a memory layer disposed between the first electrode and the second electrode,   wherein the memory layer comprises two or more memory portions and one or more ion conductor portions disposed within the two or more memory portions and/or between the two or more memory portions,   wherein each of one or more ion conductor portions is configured to allow an exchange of oxygen ions between at least two memory portions of the two or more memory portions.   
     
     
         17 . The memory cell according to  claim 16 ,
 wherein each of the one or more ion conductor portions substantially consists of a material that is both electrically insulating and capable of conducting oxygen ions.   
     
     
         18 . Memory cell, comprising:
 a first electrode,   a second electrode, and   a memory layer disposed between the first electrode and the second electrode,   wherein the memory layer comprises two or more memory portions and one or more separation portions disposed between the two or more memory portions,   wherein each of the two or more memory portions comprises a remanent-polarizable material based on at least one metal oxide,   wherein each of one or more separation portions comprises a separation material including a metal oxide that has a different chemical composition than the at least one metal oxide.   
     
     
         19 . The memory cell according to  claim 18 ,
 wherein the separation material is different from the remanent-polarizable material in at least one of an oxygen content, a stoichiometry, and/or a type of participating elements.   
     
     
         20 . The memory cell according to  claim 18 ,
 wherein the separation material comprises a substantially stoichiometric oxygen content; and   wherein the remanent-polarizable material comprises a sub-stoichiometric oxygen content.