Spin electronic memory, information recording method and information reproducing method

• US 9,984,745 B2
• Filed: 09/19/2014
• Issued: 05/29/2018
• Est. Priority Date: 11/15/2013
• Status: Expired due to Fees

• Current Assignee: National Institute of Advanced Industrial Science and Technology (Government of Japan)
• Original Assignee: National Institute of Advanced Industrial Science and Technology (Government of Japan)
• Inventors: Tominaga, Junji
• Primary Examiner(s): BERNSTEIN, ALLISON
• Application Number:
  US15/036,666
• Publication Number:
  US 20160284394A1
• Time in Patent Office: 1,348 Days
• CPC Class Codes: G06F 3/0625 Power saving in storage systems
• CPC Class Codes: G06F 3/0659 Command handling arrangements, e.g. command buffers, queues, command scheduling
• CPC Class Codes: G06F 3/0688 Non-volatile semiconductor memory arrays
• CPC Class Codes: G11C 11/161 details concerning the memory cell structure, e.g. the layers of the ferromagnetic memory cell
• CPC Class Codes: G11C 11/1673 Reading or sensing circuits or methods
• CPC Class Codes: G11C 11/1675 Writing or programming circuits or methods
• CPC Class Codes: G11C 11/18 using Hall-effect devices
• CPC Class Codes: G11C 11/5607 using magnetic storage elements
• CPC Class Codes: G11C 13/0004 comprising amorphous/crystalline phase transition cells
• CPC Class Codes: G11C 13/04 using optical elements ; using other beam accessed elements, e.g. electron or ion beam
• CPC Class Codes: H10N 50/10 Magnetoresistive devices
• CPC Class Codes: H10N 50/80 Constructional details
• CPC Class Codes: H10N 50/85 Magnetic active materials
• CPC Class Codes: H10N 70/235 between different crystalline phases, e.g. cubic and hexagonal
• CPC Class Codes: H10N 70/826 adapted for essentially vertical current flow, e.g. sandwich or pillar type devices
• CPC Class Codes: H10N 70/8828 Tellurides, e.g. GeSbTe

Abstract

A spin electronic memory of the present invention includes: a pair of electrodes 1, 2, recording layers 6a, 6b, and 6c between the electrodes 1 and 2, the recording layer being formed by laminating first alloy layer 5 and second alloy layer 4, the first alloy layer 5 being formed to contain any one of SbTe, Sb₂Te₃, BiTe, Bi₂Te₃, BiSe, and Bi₂Se₃ as a principal component and to have a thickness of 2 nm to 10 nm, the second alloy layer 4 being formed to contain an alloy expressed by general formula (1) as a principal component; and spin injection layer 7 formed with a magnetic material to inject a spin into the recording layer with the magnetic material being magnetized,
M_1-xTe_x  (1)

• • where M represents an atom selected from atoms of Ge, Al, and Si, and x represents a value of 0.5 or more and less than 1.

Claims

1. A method for recording information using a spin electronic memory, the method comprising applying voltage having voltage values staged into n stages to n recording layers laminated, the voltage values being necessary for accumulating a spin in a saturated state in each of the recording layers, where n is an integer of at least 1 or more,

wherein the spin electronic memory comprises:

a pair of electrodes;

a recording layer disposed between the electrodes, the recording layer being formed by laminating a first alloy layer and a second alloy layer, the first alloy layer being formed to contain any one of SbTe, Sb₂Te₃, BiTe, Bi₂Te₃, BiSe, and Bi₂Se₃ as a principal component and to have a thickness of 2 nm to 10 nm, the second alloy layer being formed to contain an alloy expressed by a following general formula (1) as a principal component; and

a spin injection layer formed with a magnetic material and configured to inject a spin into the recording layer with the magnetic material being magnetized,

M_1-xTe_x 

 

(1)

where M represents an atom selected from atoms of Ge, Al, and Si, and x represents a value of 0.5 or more and less than 1.

2. The method for recording information according to claim 1, wherein

the first alloy layer has a hexagonal crystal structure, and the second alloy layer has a cubic crystal structure, and

a c-axis of the first alloy layer is oriented in a laminating direction, and a (111) plane of the second alloy layer is oriented along an adjacent surface adjacent to the first alloy layer.

3. The method for recording information according to claim 1, wherein the second alloy layer is formed to contain GeTe as a principal component.

4. The method for recording information according to claim 1, wherein the second alloy layer has a thickness of more than 0 and 4 nm or less.

5. The method for recording information according to claim 1, further comprising

an orientation layer disposed as a base of the second alloy layer to orient a lamination plane of the second alloy layer laminated thereon along a (111) plane.

6. The method for recording information according to claim 5, wherein the orientation layer has a composition and a crystal structure identical to those of the first alloy layer.

7. The method for recording information according to claim 1, further comprising

a magnetic section configured to form a magnetic field in a direction perpendicular to a plane of the spin injection layer to inject a spin into the recording layer through the spin injection layer.

8. A method for reproducing information using a spin electronic memory, the method comprising measuring a status value of one of a resistance value and an optical reflectance of n recording layers laminated, and determining, based on the status value, number of the recording layers having information recorded thereon in the recording layers laminated, where n is an integer of at least 1 or more,

wherein the spin electronic memory comprises:

a pair of electrodes;

a recording layer disposed between the electrodes, the recording layer being formed by laminating a first alloy layer and a second alloy layer, the first alloy layer being formed to contain any one of SbTe, Sb₂Te₃, BiTe, Bi₂Te₃, BiSe, and Bi₂Se₃ as a principal component and to have a thickness of 2 nm to 10 nm, the second alloy layer being formed to contain an alloy expressed by a following general formula (1) as a principal component; and

a spin injection layer formed with a magnetic material and configured to inject a spin into the recording layer with the magnetic material being magnetized,

M_1-xTe_x 

 

(1)

where M represents an atom selected from atoms of Ge, Al, and Si, and x represents a value of 0.5 or more and less than 1.

9. The method for reproducing information according to claim 8, wherein

the first alloy layer has a hexagonal crystal structure, and the second alloy layer has a cubic crystal structure, and

a c-axis of the first alloy layer is oriented in a laminating direction, and a (111) plane of the second alloy layer is oriented along an adjacent surface adjacent to the first alloy layer.

10. The method for reproducing information according to claim 8, wherein

the second alloy layer is formed to contain GeTe as a principal component.

11. The method for reproducing information according to claim 8, wherein

the second alloy layer has a thickness of more than 0 and 4 nm or less.

12. The method for reproducing information according to claim 8, further comprising

an orientation layer disposed as a base of the second alloy layer to orient a lamination plane of the second alloy layer laminated thereon along a (111) plane.

13. The method for reproducing information according to claim 12, wherein

the orientation layer has a composition and a crystal structure identical to those of the first alloy layer.

14. The method for reproducing information according to claim 8, further comprising

a magnetic section configured to form a magnetic field in a direction perpendicular to a plane of the spin injection layer to inject a spin into the recording layer through the spin injection layer.