Magnetic storage device and manufacturing method of magnetic storage device

1. A magnetic storage device comprising:

a substrate;

a dummy contact disposed on a top surface of the substrate, extending linearly in a direction substantially perpendicular to the top surface of the substrate, and floating electrically;

a magnetoresistive effect element included in a layer and insulated from the dummy contact, wherein the layer is disposed on a top surface of the dummy contact;

a lower electrode disposed on a bottom surface of the magnetoresistive effect element; and

an insulating layer disposed between the top surface of the substrate and a bottom surface of the lower electrode,

wherein the magnetoresistive effect element is laterally displaced from the dummy contact, and

wherein the following relationship is satisfied:

d 2/ d 1≤TC_MTJ/TC_IL

where:

d 2 is a lateral distance between the lower electrode and a portion of the dummy contact disposed in a position closest to the magnetoresistive effect element,

d 1 is a shortest vertical distance from the lower electrode to the semiconductor substrate,

TC_MTJ is a first thermal conductivity of the magnetoresistive effect element, and

TC_IL is a second thermal conductivity of the insulating layer.

2. The device of claim 1 , wherein the substrate includes an element insulating area that insulates an area electrically connected to the dummy contact from an area electrically connected to the magnetoresistive effect element.

3. The device of claim 1 , further comprising:

a dummy magnetoresistive effect element disposed in a same layer as the magnetoresistive effect element and insulated from the magnetoresistive effect element.