Process for producing magnetic head poles utilizing sputtered materials and a recording head made thereby

#The present invention relates, in general, to the field of magnetoresistive (“MR”) and giant magnetoresistive (“GMR”) recording heads. More particularly, the present invention relates to a process for producing poles in a magnetic recording head utilizing sputtered materials and a magnetic recording head made thereby.

#MR and GMR read heads, or sensors, are known to be useful in reading data from a magnetic surface with a sensitivity exceeding that of inductive or other thin-film heads. In operation, the sensor is used to detect magnetic field signal changes encoded on a magnetic surface through a change in resistance which is exhibited due to the direction and strength of the associated magnetic flux being sensed. Currently, the magnetic field signal changes representing the data encoded on the particular storage medium is “read” by an MR or GMR read head and “written” by a related write, or recording, head. In those instances wherein the read head has associated shield layers, the write head may utilize the “top” shield as a bottom pole thereby providing what is known as a “merged” or “shared” shield pole structure. In any event, a typical thin film recording head ultimately comprises two magnetic poles, a top and bottom pole that surround a coil forming a write gap.

#In conventional magnetic recording heads, nickel iron (NiFe), or permalloy, is generally used as the pole material. However, as the recording areal density of storage devices continues to increase, more advanced pole materials having a higher magnetic moment are required. While conventional permalloy poles can be produced using well known electroplating techniques and result in relatively well defined edge profiles and good width control, many of the known high magnetic moment materials such as cobalt-zirconium-tantalum (CoZrTa), iron-aluminum-nitride (FeAlN), iron-tantalum-nitride (FeTaN) and iron nitride (FeN) can only be sputter deposited, thereby making it extremely difficult to pattern and produce well defined poles.

#The aforementioned and other features and objects of the present invention and the manner of attaining them will become more apparent and the invention itself will be best understood by reference to the following description of a preferred embodiment taken in conjunction with the accompanying drawings, wherein:

#FIG. 1A illustrates a conventional process step in the formation of a pole for a magnetic recording head in which the pole is defined by a photoresist area and wherein the structure is then subjected to a dry etching operation, such as ion milling, and which results in the undesired and continuous re-deposition of material on the sides of the pole and the photoresist area;

#FIG. 1B illustrates a follow-on operation to the conventional process step shown in FIG. 1A following the stripping of the photoresist area and wherein the re-deposited material adhering to the pole remains as undesired “bunny ears” which promote the formation of voids between them following encapsulation (or overcoat), particularly with the narrow pole widths required for higher areal recording density using relatively high magnetic moment materials;

#With reference now to FIG. 1A, a conventional process step in the formation of a pole 10 for a magnetic recording head is shown. In this example, a relatively high magnetic moment material 12 has been previously sputtered on a substrate (not shown) and the pole 10 has been defined by an overlying photoresist area. The structure has then been subjected to a dry etching operation, such as ion milling process, and an undesired and continuous re-deposition of the high magnetic moment material 12 comprising re-deposited material 16 can be observed to have occurred on the sides of the pole 10 and the photoresist area 14.

#With reference additionally to FIG. 1B, a follow-on operation to the conventional process step shown in FIG. 1A is shown following the stripping of the photoresist area 14. As can be seen, the re-deposited material 16 adhering to the pole 10 remains as undesired “bunny ears” 18 which lead to voids in subsequent encapsulation (or overcoat), particularly when used in conjunction with narrow track width heads needed for high density storage devices.

#With reference additionally now to FIGS. 2A through 2G, a representative processing sequence in accordance with the present invention is shown. As illustrated in FIG. 2A, a substrate 50 is provided for subsequent forming of a relatively high magnetic moment material layer 52 as shown in FIG. 2B. In a particular application of the present invention, the substrate 50 may comprise a shared shield with an overlying write gap material on which the MR or GMR writer is formed. The relatively high magnetic moment material layer 52 may, in a preferred embodiment, be formed in a conventional sputtering operation utilizing cobalt-zirconium-tantalum (CoZrTa), iron-aluminum-nitride (FeAlN), iron-tantalum-nitride (FeTaN), iron-nitride (FeN) or other similar materials. As shown in the following FIG. 2C, a photoresist area 54 is then patterned on the exposed surface of the relatively high magnetic moment material layer 52 to subsequently define the pole of the magnetic recording head.