Perpendicular magnetic recording head and manufacturing method thereof

A perpendicular magnetic recording head, comprising:

• a main magnetic pole layer exposed to an opposing surface opposite a recording medium, applying a perpendicular recording magnetic field to the recording medium;
• a return yoke layer disposed above or below the main magnetic pole layer, the return yoke layer receiving the recording magnetic field returning thereto after passing through the recording medium;
• a magnetoresistive element that read recording information from the recording medium using a magnetoresistance effect;
• and
• a first shield layer disposed under the magnetoresistive element,
• a second shield layer disposed under the magnetoresitive element,
• wherein each of the first and second shield layers has two side surfaces and a front end surface positioned between the two side surfaces, the front end surface being formed in the opposing surface;
• wherein a width between the two side surfaces increases as a distance from the front end surface increases;
• a first planarized nonmagnetic layer filling the surroundings of the first shield layer,
• a second planarized nonmagnetic layer filling the surroundings of the second shield layer;
• wherein a first cohesive layer is disposed between the first shield layer and the first planarized nonmagnetic layer to increase the cohesive properties between the first shield layer and the first planarized nonmagnetic layer compared with the case in which the first shield layer is directly connected to the first planarized nonmagnetic layer, and
• wherein a second cohesive layer is disposed between the second shield layer and the second planarized nonmagnetic layer to increase the cohesive properties between the second shield layer and the second planarized nonmagnetic layer compared with the case in which the second shield layer is directly connected to the second planarized nonmagnetic layer.

A manufacturing method of a perpendicular magnetic recording head, comprising:

• forming a return yoke layer having two side surfaces and a front end surface positioned between the two side surfaces, the front end surface being formed in the opposing surface;
• wherein a width between the two side surfaces increases as a distance from the front end surface increases;
• forming a cohesive layer over an upper surface and the side surfaces of the return yoke layer, the cohesive layer increasing the cohesive properties between the return yoke layer and a planarized nonmagnetic layer to be formed in a subsequent step, compared with the case in which the return yoke layer is directly connected to the planarized nonmagnetic layer;
• forming the planarized nonmagnetic layer on the cohesive layer to such a thickness that the return yoke layer and the surroundings thereof are covered;
• and
• performing a polishing process to the planarized nonmagnetic layer until the return yoke layer is exposed, thereby planarizing the upper surface of the return yoke layer.

A manufacturing method of a perpendicular magnetic recording head, comprising:

• forming a first shield layer;
• forming a magnetoresistive element on the first shield layer;
• and
• forming a second shield layer on the magnetoresistive element;
• wherein each of the first and second shield layers has two side surfaces and a front end surface positioned between the two side surfaces, the front end surface being formed in the opposing surface;
• wherein a width between the two side surfaces increases as a distance from the front end surface increases;
• wherein after forming the first shield layer, forming a cohesive layer over an upper surface and the side surfaces of the first shield layer, the first cohesive layer increasing the cohesive properties between the first shield layer and a first planarized nonmagnetic layer to be formed in a subsequent step, compared with the case in which the first shield layer is directly connected to the first planarized nonmagnetic layer;
• wherein after forming the first cohesive layer, said first planarized nonmagnetic layer is formed on the first cohesive layer to such a thickness that the first shield layer and the surroundings thereof are covered;
• wherein after forming the first planarized nonmagnetic layer is formed, the first planarized nonmagnetic layer is polished until the first shield layers is exposed, thereby planarizing an upper surface of the first shield layer;
• wherein after forming the second shield layer, a second cohesive layer is formed over an upper surface and the side surfaces of the second shield layer, the second cohesive layer increasing the cohesive properties between the second shield layer and a second planarized nonmagnetic layer to be formed in a subsequent step, compare with the case in which the second shield layer is directly connected to the second planarized nonmagnetic layer;
• wherein after forming the second cohesive layer, said second planarized nonmagnetic layer is formed on the second cohesive layer to such a thickness that the second shield layer and the surroundings thereof are covered;
• and
• wherein after forming the second planarized nonmagnetic layer, the second planarized nonmagnetic layer is polished until the second shield layer is exposed, thereby planarizing an upper surface of the second shield layer.