Magnetic memory with spin device element exhibiting magnetoresistive effect

• US 10,032,829 B2
• Filed: 11/14/2017
• Issued: 07/24/2018
• Est. Priority Date: 03/06/2015
• Status: Active Grant

• Current Assignee: Bluespin, Inc.
• Original Assignee: Bluespin, Inc.
• Inventors: Fukuzawa, Hideaki
• Primary Examiner(s): Nguyen, Hien
• Application Number:
  US15/811,942
• Publication Number:
  US 20180083066A1
• Time in Patent Office: 252 Days
• 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 11/1675 Writing or programming circuits or methods
• CPC Class Codes: H10B 61/00 Magnetic memory devices, e.g. magnetoresistive RAM [MRAM] devices
• CPC Class Codes: H10B 61/22 of the field-effect transistor [FET] type
• CPC Class Codes: H10N 30/204 using bending displacement, e.g. unimorph, bimorph or multimorph cantilever or membrane benders
• CPC Class Codes: H10N 50/10 Magnetoresistive devices
• CPC Class Codes: H10N 50/80 Constructional details

Abstract

A magnetic memory includes a deformable base plate, a spin device element coupled with the deformable base plate and storing a data as a magnetization direction, and a bending mechanism to bend the deformable base plate. At least one of upper and lower surfaces of the deformable base plate faces a space which is not filled with solid substance.

Claims

1. A method of manufacturing a magnetic memory, including:

forming a sacrificial layer on a semiconductor substrate in which a transistor is integrated;

forming a deformable base plate on the sacrificial layer;

forming a spin device element on the deformable base plate, the spin device element storing a digital data representing a magnetization direction;

forming a bending mechanism configured to bend the deformable base plate; and

forming a space which is not filled with solid substance by removing at least a portion of the sacrificial layer, so that the lower surface of the deformable base plate faces the space.

2. The method according to claim 1, wherein the bending mechanism is configured to bend the deformable base plate with a piezoelectric effect.

3. The method according to claim 2, wherein the forming the bending mechanism includes:

forming a piezoelectric layer coupled with the deformable base plate.

4. The method according to claim 1, wherein the magnetization direction is allowed to be directed in first and second directions different from each other,

wherein the first direction is associated with a first data value, and

wherein the second direction is associated with a second data value.

5. The method according to claim 1, further comprising:

forming a fixture base on the semiconductor substrate,

wherein the fixture base and the sacrificial layer are commonly formed on a surface of the semiconductor substrate,

wherein the deformable base plate are formed on the fixture base and the sacrificial layer.

6. The method according to claim 5,

wherein the portion of the sacrificial layer is selectively removed while the fixture base and the deformable base plate remain unremoved.

7. The method according to claim 1, wherein the forming of the bending mechanism includes forming a first electrode,

wherein the deformable base plate includes a second electrode opposed to the first electrode,

wherein the bending mechanism is configured to bend the deformable base plate by using a force exerted between the first and second electrodes when a voltage is applied between the first and second electrodes.

8. The method according to claim 1, wherein the spin device element is positioned opposed to the space which is not filled with solid substance, across the deformable base plate.

9. The method according to claim 8, wherein the spin device element is coupled with the upper surface of the deformable base plate, and

wherein the lower surface of the deformable base plate faces the space which is not filled with solid substance.

10. The method according to claim 1, further comprising:

forming a contact providing an electrical connection between the spin device element and the transistor through the deformable base plate.

11. The method according to claim 5, further comprising:

forming a contact providing an electrical connection between the spin device element and the transistor through the base fixture and the deformable base plate.