Semiconductor memory device and manufacturing method thereof

A semiconductor memory device comprising:

• a transistor formed within a semiconductor substrate, the transistor comprising a first diffusion layer, a second diffusion layer and a gate electrode;
• a contact layer formed on the first diffusion layer of the transistor, the contact layer being formed of a first material;
• a first layer formed around the contact layer;
• and
• a magnetic tunnel junction (MTJ) element formed at least on the contact layer,
• wherein
• the first layer in contact with a side surface of the contact layer, has a first width extending parallel to a stacking direction of the MTJ element, and a second width extending perpendicularly to the direction of extension the first width, the second width being less than the first width.

A method of manufacturing a semiconductor memory device, the method comprising:

• forming a transistor within a semiconductor substrate, the transistor comprising a first diffusion layer, a second diffusion layer and a gate electrode;
• forming a contact layer on the first diffusion layer of the transistor, the contact layer being formed of a first material;
• forming a first layer around the contact layer;
• and
• forming a magnetic tunnel junction (MTJ) element on the contact layer.