Electronic device and wiring with a current induced cooling effect, and an electronic device capable of converting a temperature difference into voltage

• US 20060056113A1
• Filed: 09/09/2005
• Published: 03/16/2006
• Est. Priority Date: 09/13/2004
• Status: Active Grant

• 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: Yamamoto, Atsushi, Kubota, Hitoshi, Fukushima, Akio
• Granted Patent: US 7,556,869 B2
• Time in Patent Office: Days
• US Class Current: 360/324.100
• CPC Class Codes: G11B 5/3903 using magnetic thin film layers or their effects, the films being part of integrated structures
• CPC Class Codes: G11B 5/40 Protective measures on heads, e.g. against excessive temperature G11B5/31 takes precedence; protection against wear G11B5/255 ; protective structure of the head: see under structures, e.g. G11B5/3106
• CPC Class Codes: G11C 11/16 using elements in which the storage effect is based on magnetic spin effect
• CPC Class Codes: H01L 23/38 Cooling arrangements using the Peltier effect
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H10N 50/10 Magnetoresistive devices
• CPC Class Codes: Y10T 428/1193 with interlaminar component [e.g., adhesion layer, etc.]

Abstract

Localized temperature increases inside integrated circuits due to heating at operation are prevented or controlled by electronic devices or wirings with CPP (current-perpendicular-to-plane) structure which has a current cooling effect. The CPP structure refers to a structure comprising a columnar electrically conductive portion and an insulator portion surrounding the conductive portion. The columnar portion is formed from the multilayered structure in a direction perpendicular to the plane of the layers, so as to allow a current to flow from an upper layer to a lower layer (or vice versa). The cooling effect is induced by current at the interface (or a plural of interfaces) of appropriately selected different kinds of materials (which are conductive substances in general, such as metals, semiconductors, and alloys thereof) in the columnar portion due to the Peltier effect when a current flows through the column. Temperature in minute range is detected by thermocouple with CPP structure. The thermocouple has two interfaces of different materials with a proper combination. When a temperature difference exists between two interfaces, a voltage which corresponds to product of the temperature difference and the Peltier coefficient at the interface is produced. In the same manner, the intensity of inferred can be also measured.

Claims

1. An electronic device with a current cooling effect, comprising a CPP structure comprising a columnar portion formed perpendicularly to the plane of films or layers, wherein current flows along said columnar portion,

wherein said CPP structure includes an interface of different kinds of materials, wherein said different kinds of materials forming said interface produce a cooling effect when current flows therethrough.

2. The electronic device according to claim 1, wherein a plurality of said interfaces of different kinds of materials produce a cooling effect in terms of said columnar structural portion as a whole when current flows therethrough.

3. The electronic device according to claim 1, wherein said different materials comprise a metal, a semiconductor, and/or an electrically conductive substance such that the absolute value of the difference between the Seebeck coefficients of the individual materials, or, when the CPP structure comprises a plurality of interfaces of different kinds of materials, the absolute value of the difference between a maximum value and a minimum value of the Seebeck coefficients of the individual materials, is not less than 10 μ

V/K, so that the cooling capacity can be enhanced.

4. The electronic device according to claim 1, wherein the CPP structure comprises a multilayered structure comprising different kinds of materials, each layer measuring 1 to several tens of nanometers thickness, wherein a cooling effect can be effectively exhibited at the junctions.

5. The electronic device according to claim 1, wherein said CPP structure has a cross section of 1 micrometer square or less, and a length of 1 micrometer or less.

6. The electronic device according to claim 1, wherein said CPP structure has a resistance-per-area of 10Ω

/micrometer-square or smaller.

7. The electronic device according to claim 1, wherein said CPP structure is provided in a giant magnetoresistance (GMR) device or in a tunneling magnetoresistance (TMR) device comprising a magnetic metal multilayered film.

8. The electronic device according to claim 7, wherein said GMR device or said TMR device is provided as a magnetic detection sensor used in a magnetic- head for a hard-disk drive.

9. The electronic device according to claim 8, wherein said CPP structure is disposed at a wiring portion for said GMR device or said TMR device.

10. The electronic device according to claim 7, wherein said GMR device or said TMR device is used as a memory cell in a magnetic random access memory.

11. The electronic device according to claim 1, wherein said CPP structure is provided in a semiconductor device as a component in a semiconductor integrated circuit with a multilayered structure.

12. A wiring structure with a cooling effect, comprising a CPP structure disposed in a semiconductor integrated circuit, said CPP structure comprising a columnar portion comprised of thin films or layers layered in a direction perpendicular to the plane of the films or layers,

wherein a current flows along said columnar portion, said wiring structure functioning solely as a lead wire to a power supply or to ground provides no electrically active function, wherein said CPP structure includes an interface of different kinds of materials, wherein said different kinds of materials forming said interface provide a cooling effect when a current flows therethrough.

13. An electronic device comprising a CPP structure comprising a columnar portion formed perpendicularly to the plane of thin films or layers,

wherein said CPP structure has two interfaces of different kinds of materials, wherein said different kinds of materials forming said interfaces are capable of detecting a temperature difference between said two interfaces.

14. The electronic device according to claim 13, wherein said two interfaces of different kinds of materials are formed by positioning between two first materials a single second material which has a different thermoelectric power from that of said first material, to join said first materials and second material.

15. The electronic device according to claim 13, wherein a plurality of said CPP structures are connected in series so that an output voltage is increased in proportion to the number of the structures.

16. The electronic device according to claim 13, which functions as a temperature sensor or an infrared sensor.