Read heads in planar monolithic integrated circuit chips
AssigneeNVE Corporation
InventorsJames M. Daughton, Arthur V. Pohm
Life of this patent
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Abstract
A plurality of magnetic field sensing structures in a monolithic integrated circuit chip structure to provide output signals at outputs thereof of magnetic field changes provided therein from corresponding sources having poled pair structures with a gap space between them with adjacent ones of the magnetic field sensing structures that are interconnected with a circuit formed in the monolithic integrated circuit chip such as an amplifier. The paired pole structures may intersect a surface of the chip perpendicular to the major surfaces thereof or in one of, or a surface parallel to, the major surfaces thereof. A magnetic field generating structure may also be included in the chip.
Claims35
A plurality of magnetic field sensors in a multiple sensor structure having a substrate, said magnetic field sensors providing at corresponding outputs thereof representations of magnetic field changes provided therein from a corresponding source of such magnetic field changes, said sensor structure comprising:
- a plurality of paired pole structures supported on said substrate with each of those pole structures in a said paired pole structure being spaced apart from one another to form a corresponding gap space therebetween and with each of said pole structures comprising a permeable material and having an end thereof substantially in a common surface;
- and
- a plurality of field sensing structures each supported on said substrate adjacent a corresponding paired pole structure with at least a portion thereof positioned away from said common surface, each of said plurality field sensing structures being formed of a plurality of magnetoresistive, anisotropic, ferromagnetic thin-film layers at least two of which are separated from one another by a nonmagnetic layer positioned therebetween.
A plurality of magnetic field sensors in a multiple sensor structure having a substrate, said magnetic field sensors providing at corresponding outputs thereof representations of magnetic field changes provided therein from a corresponding source of such magnetic field changes, said sensor structure comprising:
- at least one paired pole structure supported on said substrate with each of those pole structures in said paired pole structure being spaced apart from one another to form a corresponding gap space therebetween and with each of said pole structures comprising a permeable material and having an end thereof substantially in a common surface;
- and
- a plurality of field sensing structures each supported on said substrate adjacent a corresponding paired pole structure with at least a portion thereof positioned away from said common surface, each of said plurality field sensing structures being formed of a plurality of magnetoresistive, anisotropic, ferromagnetic thin-film layers at least two of which are separated from one another by a nonmagnetic layer positioned therebetween.
A method for fabricating a magnetic field sensor in a sensor structure on a substrate, said method comprising:
- providing an initial permeable material layer on a surface of said substrate having an opening therein with an angled side formed at an angle with respect to said substrate surface;
- providing an initial nonmagnetic material layer supported by said initial permeable material layer including supported by said angled side thereof;
- providing a device permeable material layer supported by at least one of said initial nonmagnetic material layer and an electrical interconnection extending therethrough, said device permeable material layer at least in part to be a portion of a magnetic sensing structure;
- providing a device nonmagnetic material layer on said device permeable material layer which is at least in part to be a portion of a magnetic sensing structure;
- providing a completion permeable material layer on said nonmagnetic material layer which is at least in part to be a portion of a magnetic sensing structure, at least one of said device permeable material layer and said completion permeable material layer also being provided across from said angled side;
- and
- removing portions of at least said initial nonmagnetic material layer and at least one of said device permeable material layer and said completion permeable material layer to form a common surface intersected by such layers which common surface intersects at least a portion of said angled side.
Dependencies are inferred from the claim text.