Magnetoresistance sensors pinned by an etch induced magnetic anisotropy

#1. Field of the Invention

#The invention is related to the field of magnetic recording head fabrication, and in particular, to improved methods of fabricating a magnetoresistance sensor that is pinned by an etch induced magnetic anisotropy.

#2. Statement of the Problem

#The same reference number represents the same element or same type of element on all drawings.

#FIG. 1 is a cross sectional view of a prior art magnetoresistance sensor.

#FIG. 2 is a flow chart illustrating an exemplary method for fabricating a magnetoresistance sensor that is pinned with an etch induced magnetic anisotropy.

#FIG. 1 is a schematic illustration of a prior art magnetoresistance sensor (MR) 100. MR sensor 100 includes a shield layer 102 formed on a wafer substrate (not shown). MR sensor 100 also includes one or more seed layers 104 formed on shield layer 102 to facilitate a desired grain structure fabrication of subsequently deposited layers of MR sensor 100. MR sensor 100 also includes an AFM pinning layer 106 formed on seed layer 104. MR sensor 100 also includes a magnetic pinned layer 108 formed on an AFM pinning layer 106. Magnetic pinned layer 108 has its magnetization fixed by exchange coupling with AFM pinning layer 106. A spacer layer 110 is formed on magnetic pinned layer 108. A magnetic free layer 112 is formed on spacer layer 110. The magnetization of magnetic free layer 112 is not fixed and is free to rotate in response to an external magnetic field. A cap layer 114 may be formed on free layer 112 to protect the layers of MR sensor 100 from damage during the fabrication process. A shield layer 116 is formed on cap layer 114.

#The size of MR sensor 100 and the number of layers forming MR sensor 100 is a problem for higher density magnetic recording devices. Particularly, the size of AFM pinning layer 106 is a problem, because AFM pinning layer 106 requires a large fraction of the space on MR sensor 100 and causes parasitic resistance in the read signal. The present invention eliminates the size problem of AFM pinning layer 106 and parasitic resistance of AFM pinning layer 106 by eliminating AFM pinning layer 106 from MR sensor 100. Instead, an etch induced magnetic anisotropy pins the magnetization of magnetic pinned layer 108.

#FIGS. 2-7 and the following description depict specific exemplary embodiments of the invention to teach those skilled in the art how to make and use the invention. For the purpose of teaching inventive principles, some conventional aspects of the invention have been simplified or omitted. Those skilled in the art will appreciate variations from these embodiments that fall within the scope of the invention. Those skilled in the art will appreciate that the features described below can be combined in various ways to form multiple variations of the invention. As a result, the invention is not limited to the specific embodiments described below, but only by the claims and their equivalents.