Magnetic tunnel junction element, magnetic memory using the same, and manufacture method of magnetic tunnel junction element

A manufacture method of magnetic tunnel junction element for manufacturing a magnetic tunnel junction element from a laminate layer which includes:

• a magnetic tunnel junction layer including a first ferromagnetic layer, a first tunnel barrier and a second ferromagnetic layer that are laminated on top of each other in this order;
• a cap layer;
• and a hard mask layer which are laminated on top of each other in this order, the method comprising:
• a first step of etching the cap layer and the magnetic tunnel junction layer by using the patterned hard mask layer;
• a second step of forming a first SiN layer by plasma CVD on side walls of the hard mask layer, the cap layer and the magnetic tunnel junction layer, and
• a third step of forming by plasma CVD a second SiN layer which covers the first SiN layer,
• wherein a hydrogen ion density or hydrogen ion energy in the second step is lower than a hydrogen ion density or hydrogen ion energy in the third step, and
• the second SiN layer is formed in the third step under a layer forming condition that a density of nitrogen in the second SiN layer is higher than a density of nitrogen in the first SiN layer.

A manufacture method of magnetic tunnel junction element for manufacturing a magnetic tunnel junction element from a laminate layer which includes:

• a magnetic tunnel junction layer including a first ferromagnetic layer, a first tunnel barrier and a second ferromagnetic layer that are laminated on top of each other in this order;
• a cap layer;
• and a hard mask layer which are laminated on top of each other in this order,
• the method comprising:
• a first step of etching the cap layer and the magnetic tunnel junction layer by using the patterned hard mask layer;
• a second step of forming by plasma CVD a first SiN layer on side walls of the hard mask layer, the cap layer and the magnetic tunnel junction layer,
• a third step of forming by plasma CVD a second SiN layer which covers the first SiN layer, and
• a fourth step of forming by plasma CVD a third SiN layer which covers the second SiN layer,
• wherein a hydrogen ion density or hydrogen ion energy in the second step is lower than a hydrogen ion density or hydrogen ion energy in the third step and the fourth step,
• the second SiN layer is formed in the third step under a layer forming condition that moisture resistance of the second SiN layer is higher than moisture resistance of the first SiN layer and the third SiN layer, and
• the third SiN layer is formed in the fourth step under a layer forming condition that a density of nitrogen in the third SiN layer is higher than a density of nitrogen in the first SiN layer and the second SiN layer.