Magnetic recording head and method for manufacturing
View Patent ↗A thin-film magnetic head having little temperature rise in the element, good heat dissipation and a short magnetic path length (narrow coil pitch) and manufacturing method for same is provided. To form the coil of the thin-film magnetic head, a lower coil is first formed and after forming alumina and an inorganic compound containing alumina, a trench is formed for the upper coil by reactive ion etching. The lower coil allows uniform etching at this time and functions as a film to prevent loading effects occurring during reactive ion etching. This trench is then plated in copper and chemical mechanical planarization performed to form the upper layer coil as the dual-layer coil of the present invention. Heat from the coil is efficiently radiated towards the substrate by alumina and an inorganic compound containing alumina with good heat propagation. The ratio of alumina or inorganic compound containing alumina in the lower coil can be selected by reactive ion etching so that an upper coil trench functioning as an etching stopper can be securely formed to allow forming a stable coil film thickness and a short magnetic path length.
1. A magnetic head comprising a lower shield layer, upper shield layer, magnetoresistive layer element formed between said lower shield layer and said upper shield layer, a lower layer magnetic pole, an upper layer magnetic pole and a coil, wherein said coil is composed of a lower coil contacting with an upper coil, and the width of said lower coil is larger than the width of said upper coil, and wherein said lower coil is composed of an etching stop layer.
2. A magnetic head according to claim 1 , wherein said coil is enclosed in insulating material and said insulating material is an inorganic compound of one or more types selectable at least from among Al 2 O 3 , SiO 2 , ZrO 2 .
3. A magnetic head according to claim 1 , wherein said magnetoresistive layer element is composed of a plurality of laminated materials containing at least a first ferromagnetic layer, an intermediate layer, and a second ferromagnetic layer; and the magnetization direction of said first ferromagnetic layer is fixed with respect to the magnetic field signal to be sensed, the magnetization of said second ferromagnetic layer rotates according to said magnetic field signal.
4. A magnetic head according to claim 3 , wherein said intermediate layer is a tunnel barrier layer, an electrode is formed to allow sensing current to pass the boundary between said first ferromagnetic layer and said tunnel barrier layer, and the boundary between said tunnel barrier layer and said second ferromagnetic layer.
5. A magnetic head according to claim 4 , wherein said tunnel barrier layer is composed of at least one of aluminum oxide, silicon oxide, zirconium oxide, hafnium oxide, tantalum oxide, magnesium oxide, aluminum nitride, silicon nitride, zirconium nitride, and hafnium nitride.
6. A magnetic head according to claim 3 , wherein said intermediate layer is an antiferromagnetic layer, and an electrode is formed to allow sensing current to pass the boundary between said first ferromagnetic layer and antiferromagnetic layer, and the boundary between antiferromagnetic layer and said second ferromagnetic layer boundary.
7. A magnetic head according to claim 3 , wherein said intermediate layer is composed of a conductive material and one material selected from among at least oxides, nitrides, carbides and boride groups; and an electrode is formed so that sensing current passes through the boundary between said first ferromagnetic layer and said intermediate layer, and the boundary between said intermediate layer and said second ferromagnetic layer.
8. A magnetic head according to claim 7 , wherein said intermediate layer is a laminated material composed of a copper layer; an oxidized layer of thin film containing at least one element from among cobalt, iron, and nickel; and a second copper layer.
9. A magnetic head comprising a lower shield layer, upper shield layer, magnetoresistive layer element formed between said lower shield layer and said upper shield layer, a lower layer magnetic pole, an upper layer magnetic pole and a coil, wherein said coil is composed of a lower coil stacked directly in contact with an upper coil, and the width of said lower coil is larger than the width of said upper coil, and wherein said lower coil is composed of an etching stop layer.
10. A magnetic head according to claim 9 , wherein said coil is enclosed in insulating material and said insulating material is an inorganic compound of one or more types selectable at least from among Al 2 O 3 , SiO 2 , ZrO 2 .
11. A magnetic head according to claim 9 , wherein said magnetoresistive layer element is composed of a plurality of laminated materials containing at least a first ferromagnetic layer, an intermediate layer, and a second ferromagnetic layer; and the magnetization direction of said first ferromagnetic layer is fixed with respect to the magnetic field signal to be sensed, the magnetization of said second ferromagnetic layer rotates according to said magnetic field signal.
12. A magnetic head according to claim 11 , wherein said intermediate layer is a tunnel barrier layer, an electrode is formed to allow sensing current to pass the boundary between said first ferromagnetic layer and said tunnel barrier layer, and the boundary between said tunnel barrier layer and said second ferromagnetic layer.
13. A magnetic head according to claim 12 , wherein said tunnel barrier layer is composed of at least one of aluminum oxide, silicon oxide, zirconium oxide, hafnium oxide, tantalum oxide, magnesium oxide, aluminum nitride, silicon nitride, zirconium nitride, and hafnium nitride.
14. A magnetic head according to claim 11 , wherein said intermediate layer is an antiferromagnetic layer, and an electrode is formed to allow sensing current to pass the boundary between said first ferromagnetic layer and antiferromagnetic layer, and the boundary between antiferromagnetic layer and said second ferromagnetic layer boundary.
15. A magnetic head according to claim 11 , wherein said intermediate layer is composed of a conductive material and one material selected from among at least oxides, nitrides, carbides and boride groups; and an electrode is formed so that sensing current passes through the boundary between said first ferromagnetic layer and said intermediate layer, and the boundary between said intermediate layer and said second ferromagnetic layer.
16. A magnetic head according to claim 15 , wherein said intermediate layer is a laminated material composed of a copper layer; an oxidized layer of thin film containing at least one element from among cobalt, iron, and nickel; and a second copper layer.
17. A magnetic head comprising a lower shield layer, upper shield layer, magnetoresistive layer element formed between said lower shield layer and said upper shield layer, a main pole, a return pole, and a coil, wherein said coil is composed of a lower coil contacting with an upper coil, and the width of said lower coil is larger than the width of said upper coil, and wherein said lower coil is composed of an etching stop layer.
18. A magnetic head according to claim 17 , wherein said coil is enclosed in insulating material and said insulating material is an inorganic compound of one or more types selectable at least from among Al 2 O 3 , SiO 2 , ZrO 2 .
19. A magnetic head according to claim 17 , wherein said magnetoresistive layer element is composed of a plurality of laminated materials containing at least a first ferromagnetic layer, an intermediate layer, and a second ferromagnetic layer; and the magnetization direction of said first ferromagnetic layer is fixed with respect to the magnetic field signal to be sensed, the magnetization of said second ferromagnetic layer rotates according to said magnetic field signal.
20. A magnetic head according to claim 19 , wherein said intermediate layer is a tunnel barrier layer, an electrode is formed to allow sensing current to pass the boundary between said first ferromagnetic layer and said tunnel barrier layer, and the boundary between said tunnel barrier layer and said second ferromagnetic layer.
21. A magnetic head according to claim 20 , wherein said tunnel barrier layer is composed of at least one of aluminum oxide, silicon oxide, zirconium oxide, hafnium oxide, tantalum oxide, magnesium oxide, aluminum nitride, silicon nitride, zirconium nitride, and hafnium nitride.
22. A magnetic head according to claim 19 , wherein said intermediate layer is an antiferromagnetic layer, and an electrode is formed to allow sensing current to pass the boundary between said first ferromagnetic layer and antiferromagnetic layer, and the boundary between antiferromagnetic layer and said second ferromagnetic layer boundary.
23. A magnetic head according to claim 19 , wherein said intermediate layer is composed of a conductive material and one material selected from among at least oxides, nitrides, carbides and boride groups; and an electrode is formed so that sensing current passes through the boundary between said first ferromagnetic layer and said intermediate layer, and the boundary between said intermediate layer and said second ferromagnetic layer.
24. A magnetic head according to claim 23 , wherein said intermediate layer is a laminated material composed of a copper layer; an oxidized layer of thin film containing at least one element from among cobalt, iron, and nickel; and a second copper layer.