NONVOLATILE MEMORY ELEMENTS HAVING CONDUCTIVE STRUCTURES WITH SEMIMETALS AND/OR SEMICONDUCTORS
A memory element programmable between different impedance states, comprising: a first electrode layer comprising a semimetal or semiconductor (semimetal/semiconductor) and at least one other first electrode element; a second electrode; and a switch layer formed between the first and second electrodes and comprising an insulating material; wherein atoms of the semimetal/semiconductor provide a reversible change in conductivity of the switch layer by application of electric fields.
1 . A memory element programmable between different impedance states, comprising:
a first electrode layer comprising a semimetal or semiconductor (semimetal/sem iconductor) and at least one other first electrode element;
a second electrode; and
a switch layer formed between the first and second electrodes and comprising an insulating material; wherein
atoms of the semimetal/semiconductor provide a reversible change in conductivity of the switch layer by application of electric fields.
2 . The memory element of claim 1 , wherein:
the semimetal/sem iconductor is selected from the group of: (C) Carbon, (Te) Tellurium, (Sb) Antimony, (As) Arsenic, (Ge) Germanium, (Si) Silicon, (Bi) Bismuth, (Sn) Tin, (S) Sulfur, (Se) Selenium, for example.
3 . The memory element of claim 1 , wherein:
the at least one other first electrode element is a transition metal selected from any of groups (columns) 3-8 of the periodic table.
4 . The memory element of claim 3 , wherein:
the semimetal/semiconductor is tellurium.
5 . The memory element of claim 3 , wherein:
the at least one other first electrode element is a transition metal selected from any of groups (columns) 3-6 of the periodic table.
6 . The memory element of claim 1 , wherein:
the at least one other first electrode element is selected from the group of: (Sc) Scandium, (Y) Yttrium, (Ti) Titanium, (Zr) Zirconium, (Hf) Hafnium, (V) Vanadium, (Nb) Niobium, (Ta) Tantalum, (Cr) Chromium, (Mo) Molybdenum, (W) Tungsten, and (Lu) Lutetium.
7 . The memory element of claim 1 , wherein:
the first electrode element comprises about 25-75 atomic percent of the other first electrode element.
8 . The memory element of claim 7 , wherein:
the first electrode element comprises about 30-60 atomic percent of the other first electrode element.
9 . The memory element of claim 8 , wherein:
the other first electrode element is selected from the group of: (Ti) Titanium, (Zr) Zirconium and (Hf) Hafnium.
10 . The memory element of claim 7 , wherein:
the first electrode element comprises about 30-50 atomic percent of the other first electrode element.
11 . The memory element of claim 10 , wherein:
the other first electrode element is selected from the group of: (Cr) Chromium, (Mo) Molybdenum and (W) Tungsten.
12 . The memory element of claim 7 , wherein:
the first electrode element comprises about 40-60 atomic percent of the other first electrode element.
13 . The memory element of claim 12 , wherein:
the other first electrode element is selected from the group of: (V) Vanadium, (Nb) Niobium and (Ta) Tantalum.
14 . The memory element of claim 1 , wherein:
an atomic percent ratio between the semimetal/sem iconductor to the other first electrode element is in the range of about 0.33-3.0.
15 . The memory element of claim 14 , wherein:
an atomic percent ratio between the semimetal/sem iconductor to the other first electrode element is in the range of about 0.43-1.5.
16 . The memory element of claim 15 , wherein:
the other first electrode element is selected from the group of: (Ti) Titanium, (Zr) Zirconium and (Hf) Hafnium.
17 . The memory element of claim 14 , wherein:
an atomic percent ratio between the semimetal/sem iconductor and the other first electrode element is in the range of about 0.67-1.5.
18 . The memory element of claim 15 , wherein:
the other first electrode element is selected from the group of: (V) Vanadium, (Nb) Niobium and (Ta) Tantalum.
19 . The memory element of claim 14 , wherein:
an atomic percent ratio between the semimetal/sem iconductor and the other first electrode element is in the range of about 0.43-1.0.
20 . The memory element of claim 19 , wherein:
the other first electrode element is selected from the group of: (Cr) Chromium and (Mo) Molybdenum.
21 . The memory element of claim 1 , wherein the switch layer comprises at least oxygen.
22 . The memory element of claim 21 , wherein the switch layer further comprises at least one other switch layer element.
23 . The memory element of claim 22 , wherein:
the at least one other switch layer element is the same as the at least one other first electrode element.
24 . The memory element of claim 22 , wherein:
the at least one other switch layer element is an alkali earth metal, transition metal, post transition metal, or metalloid selected from groups (columns) 2-6 and 13-16 of the periodic table.
25 . The memory element of claim 22 , wherein:
the at least one other switch layer element is selected from the group of: (Mg) Magnesium, (Ca) Calcium, (Sr) Strontium, (Sc) Scandium, (Y) Yttrium, (Ti) Titanium, (Zr) Zirconium, (Hf) Hafnium, (V) Vanadium, (Nb) Niobium, (Ta) Tantalum, (Mo) Molybdenum, (W) Tungsten, (Al) Aluminum, (Si) Silicon, (Ge) Germanium, (Te) Tellurium, and (Lu) Lutetium.
26 . The memory element of claim 22 , wherein:
the at least one other switch layer comprises a binary oxide of the other switch layer element.
27 . The memory element of claim 26 , wherein:
the stoichiometry of the binary oxide is M x O y , where M is the other switch layer element and O is oxygen, and the ratio of x:y is in the range of about 1:0.8 to 1:3.2.
28 . The memory element of claim 26 , wherein:
the other switch layer element is selected from groups (columns) 2-6 of the periodic table.