Magnetoresistive element, spin mosfet, and spin-transport element

Patent metadata

Field	Value
Publication number	US-2016293740-A1
Application number	US-201415038281-A
Country	US
Kind code	A1
Filing date	Nov 19, 2014
Priority date	Nov 20, 2013
Publication date	Oct 6, 2016
Grant date	—

Abstract

The magnetoresistive element includes a semiconductor channel layer, a pinned layer disposed on the semiconductor channel layer via a first tunnel layer, a free layer disposed on the semiconductor channel layer via a second tunnel layer, wherein the semiconductor channel layer includes a first region containing an interface with the first tunnel layer, a second region containing an interface with the second tunnel layer, and a third region, impurity concentrations in the first and second regions are higher than 1×10 19 cm −3 , an impurity concentration in the third region is 1×10 19 cm −3 or less, the first and second regions are separated by the third region, and the impurity concentrations in the first and second regions decrease in the thickness direction of the semiconductor channel layer from the interface between the semiconductor channel layer and the first tunnel layer and the interface between the semiconductor channel layer and the second tunnel layer.

First claim

1 . A magnetoresistive element comprising
a semiconductor channel layer,
a pinned layer disposed on the semiconductor channel layer via a first tunnel layer, and
a free layer disposed on the semiconductor channel layer via a second tunnel layer,
wherein
the semiconductor channel layer substantially consists of a first region containing an interface with the first tunnel layer, a second region containing an interface with the second tunnel layer, and a third region,
impurity concentrations in the first region and the second region are higher than 1×10 19 cm −3 , and an impurity concentration in the third region is 1×10 19 cm −3 or less, the first region and the second region are separated by the third region, and
the impurity concentrations in the first region and the second region decrease monotonically from the interface between the semiconductor channel layer and the first tunnel layer and the interface between the semiconductor channel layer and the second tunnel layer in the thickness direction of the semiconductor channel layer, respectively.

2 . The magnetoresistive element according to claim 1 , wherein
the first region and the second region have thicknesses of 10 nm or less.

3 . The magnetoresistive element according to claim 1 , wherein,
the semiconductor channel layer comprises a first projection part and a second projection part, the first region is contained in the first projection part and the second region is contained in the second projection part.

4 . The magnetoresistive element according to claim 1 , wherein,
the maximal impurity concentrations in the first region and the second region range from 2×10 19 cm −3 to 2×10 20 cm −3 .

5 . The magnetoresistive element according to claim 1 , wherein,
the third region comprises a fourth region to which a gate voltage is applied, and an impurity concentration in the fourth region is 3×10 18 cm −3 or less.

6 . The magnetoresistive element according to claim 1 , wherein,
the impurity concentrations in the third region and the fourth region decrease with increasing distances from the first region and the second region, or do not increase even with the increasing distances from the first region and the second region.

7 . The magnetoresistive element according to claim 1 , wherein,
the areal resistance between the pinned layer and the first region and the areal resistance between the free layer and the second region are both lower than 1×10 6 Ω·μm 2 .

8 . A Spin-MOSFET using the magnetoresistive element according to claim 1 .

9 . A spin-transport element using pure spin current, comprising
the magnetoresistive element according to claim 1 . a first reference electrode which is made of non-magnetic material and is disposed on a side closer to the pinned layer of outer sides of the pinned layer and the free layer, and a second reference electrode which is made of non-magnetic material and is disposed on a side closer to the free layer of outer sides of the pinned layer and the free layer.

Assignees

• Tdk Corp

Inventors

• Sasaki Tomoyuki
• Oikawa Tohru

Classifications

• H10D62/165

  Tunnel injectors · CPC title

• H10D62/149

  Source or drain regions of field-effect devices · CPC title

• H10D48/40

  Devices controlled by magnetic fields · CPC title

• H10D48/385 Primary

  Devices using spin-polarised carriers · CPC title

• H01L29/82

  Electricity · mapped topic