Semiconductor device, semiconductor device control method and optical switch

1. A semiconductor device comprising:

a first electrode configured to flow an in-plane current;

a cell arranged on the first electrode and including a magnetic tunnel junction (MTJ) having a free magnetic layer and a pinned magnetic layer with a dielectric layer in between them; and

a heating element to form a thermal gradient in the first electrode that changes a critical current of the cell.

2. The semiconductor device according to claim 1 , wherein a magnetization direction of the free magnetic layer is aligned in a perpendicular direction to a film direction of the cell to have a perpendicular anisotropy.

3. The semiconductor device according to claim 1 , wherein the heating element is arranged on the first electrode.

4. The semiconductor device according to claim 1 , wherein a direction in which the thermal gradient is formed by the heating element is a current direction applied on the first electrode.

5. The semiconductor device according to claim 1 , wherein the magnetization direction of the free magnetic layer is changed by the thermal gradient formed by the heating element.

6. The semiconductor device according to claim 1 , wherein the first electrode has a thickness or a width gradient in a current direction.

7. The semiconductor device according to claim 1 , wherein the heating element comprises a heating device.

8. The semiconductor device according to claim 1 , wherein the heating element comprises a material having a conductivity greater than that of the first electrode.

9. The semiconductor device according to claim 1 , further comprising an insulation structure formed on at least a portion of the first electrode.

10. The semiconductor device according to claim 1 , further comprising a heat dissipating structure formed on at least a portion of the first electrode.

11. A method for controlling a semiconductor device comprising a first electrode configured to flow an in-plane current, a cell arranged on a first electrode and including a magnetic tunnel junction (MTJ) having a free magnetic layer and a pinned magnetic layer with a dielectric layer in between them, and a heating element to form a thermal gradient in the first electrode that changes a critical current of the cell, comprising the following steps of:

changing the critical current value of the cell by forming the thermal gradient in the first electrode; and

saving information on the cell by applying current in the first electrode.

12. The method for controlling the semiconductor device according to claim 11 , further comprising the step of:

reading the information of the cell by applying current through the cell.

13. The method for controlling the semiconductor device according to claim 11 , wherein forming the thermal gradient in the first electrode is performed by applying current on the heating element.

14. The method for controlling the semiconductor device according to claim 11 , wherein forming the thermal gradient in the first electrode is performed by irradiating lights to the first electrode.

15. An optical switch comprising:

a first electrode configured to flow an in-plane current; and

a cell arranged on a first electrode and including a magnetic tunnel junction (MTJ) having a free magnetic layer and a pinned magnetic layer with a dielectric layer in between them, wherein the first electrode comprises a light receiving element configured to produce a thermal gradient in the first electrode that changes a critical current of the cell.

16. The optical switch according to claim 15 , wherein the light receiving element change temperature by receiving an external energy source.