Variable resistance materials with superior data retention characteristics
View Patent ↗Variable resistance memory compositions and devices exhibiting superior data retention characteristics at elevated temperature. The compositions are composite materials that include a variable resistance component and an inert component. The variable resistance component may include a phase-change material and the inert component may include a dielectric material. The phase-change material may include Ge, Sb, and Te, where the atomic concentration of Sb is between 3% and 16% and/or the Sb/Ge ratio is between 0.07 and 0.68 and/or the Ge/Te ratio is between 0.6 and 1.1 and/or the concentration of dielectric component (expressed as the sum of the atomic concentrations of the constituent elements thereof) is between 5% and 50%. The compositions exhibit high ten-year data retention temperatures and long data retention times at elevated temperatures.
1. A composite material comprising:
a phase-change component, said phase-change component comprising Ge, Sb, and Te; said Ge having an atomic concentration in said composite material between 23% and 45%; said Sb having an atomic concentration in said composite material between 3% and 16%; the ratio of said atomic concentration of Sb to said atomic concentration of Ge in said composite material being between 0.07 and 0.68; the ratio of said atomic concentration of Ge to the atomic concentration of Te in said composite material being between 0.6 and 1.1; and
an inactive component dispersed within said phase-change component, said inactive component comprising a dielectric material, the sum of the atomic concentrations of the constituent elements of said dielectric material in said composite material being between 5% and 50%.
2. The composite material of claim 1 , wherein said atomic concentration of Sb in said composite material is between 5% and 15%.
3. The composite material of claim 1 , wherein said atomic concentration of Ge in said composite material is between 30% and 40%.
4. The composite material of claim 3 , wherein said atomic concentration of Sb in said composite material is between 6.5% and 12%.
5. The composite material of claim 1 , wherein said ratio of said atomic concentration of Sb to said atomic concentration of Ge ratio in said composite material is between 0.14 and 0.58.
6. The composite material of claim 1 , wherein the melting point of said inactive component is higher than the melting point of said phase-change component.
7. The composite material of claim 1 , wherein said sum of said atomic concentrations of said constituent elements of said dielectric material in said composite material is between 9% and 35%.
8. The composite material of claim 7 , wherein said atomic concentration of Sb in said composite material is between 5% and 15%.
9. The composite material of claim 8 , wherein said atomic concentration of Ge in said composite material is between 30% and 40%.
10. The composite material of claim 9 , wherein said ratio of said atomic concentration of Sb to said atomic concentration of Ge in said composite material is between 0.14 and 0.58.
11. The composite material of claim 10 , wherein said ratio of said atomic concentration of Ge to said atomic concentration of Te in said composite material is between 0.75 and 1.0.
12. The composite material of claim 11 , wherein said sum of said atomic concentrations of said constituent elements of said dielectric material in said composite material is between 13% and 30%.
13. The composite material of claim 12 , wherein said atomic concentration of Sb in said composite material is between 6.5% and 12%.
14. The composite material of claim 13 , wherein said ratio of said atomic concentration of Sb to said atomic concentration of Ge in said composite material is between 0.16 and 0.48.
15. The composite material of claim 14 , wherein said ratio of said atomic concentration of Ge to said atomic concentration of Te in said composite material is between 0.8 and 0.95.
16. The composite material of claim 15 , wherein said sum of the atomic concentrations of said constituent elements of said dielectric material in said composite material is between 18% and 25%.
17. The composite material of claim 16 , wherein said ratio of said atomic concentration of Sb to said atomic concentration of Ge in said composite material is between 0.22 and 0.48.
18. The composite material of claim 7 , wherein said atomic concentration of Sb in said composite material is between 5% and 9%.
19. The composite material of claim 18 , wherein said ratio of the atomic concentration of Sb to said atomic concentration of Ge in said composite material is between 0.16 and 0.28.
20. The composite material of claim 19 , wherein said atomic concentration of Ge in said composite material is between 30% and 40%.
21. The composite material of claim 20 , wherein said ratio of the atomic concentration of Ge to said atomic concentration of Te in said composite material is between 0.75 and 1.0.
22. The composite material of claim 21 , wherein said sum of said atomic concentrations of said constituent elements of said dielectric material in said composite material is between 13% and 30%.
23. The composite material of claim 22 , wherein said ratio of said atomic concentration of Ge to said atomic concentration of Te in said composite material is between 0.8 and 0.95.
24. The composite material of claim 23 , wherein said sum of said atomic concentrations of said constituent elements of said dielectric material in said composite material is between 18% and 25%.
25. The composite material of claim 7 , wherein said atomic concentration of Sb in said composite material is between 13% and 16%.
26. The composite material of claim 25 , wherein said ratio of said atomic concentration of Sb to said atomic concentration of Ge in said composite material is between 0.43 and 0.53.
27. The composite material of claim 26 , wherein said atomic concentration of Ge in said composite material is between 30% and 40%.
28. The composite material of claim 27 , wherein said ratio of the atomic concentration of Ge to said atomic concentration of Te in said composite material is between 0.75 and 1.0.
29. The composite material of claim 28 , wherein said sum of the atomic concentrations of said constituent elements of said dielectric material in said composite material is between 13% and 30%.
30. The composite material of claim 29 , wherein said ratio of said atomic concentration of Ge to said atomic concentration of Te in said composite material is between 0.8 and 0.95.
31. The composite material of claim 30 , wherein said sum of said atomic concentrations of said constituent elements of said dielectric material in said composite material is between 18% and 25%.
32. The composite material of claim 1 , wherein said dielectric material comprises Si, said Si having an atomic concentration between 2% and 15% in said composite material.
33. The composite material of claim 32 , wherein said atomic concentration of Sb in said composite material is between 5% and 15%.
34. The composite material of claim 33 , wherein said atomic concentration of Si in said composite material is between 3% and 10%.
35. The composite material of claim 34 , wherein said atomic concentration of Ge in said composite material is between 30% and 40% and said ratio of the atomic concentration of said Ge to said atomic concentration of said Te in said composite material is between 0.75 and 1.0.
36. The composite material of claim 32 , wherein said atomic concentration of Sb in said composite material is between 5% and 9%.
37. The composite material of claim 36 , wherein said atomic concentration of Si in said composite material is between 5% and 8%.
38. The composite material of claim 37 , wherein said atomic concentration of Ge in said composite material is between 30% and 40% and said ratio of the atomic concentration of said Ge to said atomic concentration of said Te in said composite material is between 0.75 and 1.0.
39. The composite material of claim 32 , wherein said atomic concentration of Sb in said composite material is between 13% and 16%.
40. The composite material of claim 39 , wherein said atomic concentration of Si in said composite material is between 5% and 8%.
41. The composite material of claim 40 , wherein said atomic concentration of Ge in said composite material is between 30% and 40% and said ratio of said atomic concentration of said Ge to said atomic concentration of said Te in said composite material is between 0.75 and 1.0.