DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] FIG. 1 is a top plan view that depicts significant components of a hard disk drive which includes the magnetic head of the present invention. The hard disk drive 10 includes a magnetic media hard disk 12 that is rotatably mounted upon a motorized spindle 14 . An actuator arm 16 is pivotally mounted within the hard disk drive 10 with a magnetic head 20 of the present invention disposed upon a distal end 22 of the actuator arm 16 . A typical hard disk drive 10 may include a plurality of disks that are rotatably mounted upon the spindle 14 and a plurality of actuator arms 16 having a magnetic head 20 mounted upon the distal end 22 of the actuator arms. As is well known to those skilled in the art, when the hard disk drive 10 is operated, the hard disk 12 rotates upon the spindle 14 and the magnetic head 20 acts as an air bearing slider that is adapted for flying above the surface of the rotating disk. The slider includes a substrate base upon which the various structures that form the magnetic head are fabricated. Such heads are fabricated in large quantities upon a wafer substrate and subsequently sliced into discrete magnetic heads 20 .

[0033] As is well known to those skilled in the art typical magnetic head fabrication steps generally include the deposition and patterning of various thin film layers to fabricate a read head, followed by the further deposition and patterning of various thin film layers upon the read head to fabricate a write head. The present invention relates to the fabrication of a write head, and therefore a magnetic head of the present invention may include most, if not all, of the various read head configurations as are generally known to those skilled in the art. Thus, a detailed description of the fabrication process of the present invention can commence at a point in the magnetic head fabrication process that a read head element has been fabricated upon a wafer substrate, followed by the fabrication of a P 1 magnetic pole and a write gap layer. Such structures are well known to those skilled in the art, and a detailed description thereof is not required to present a detailed description of the present invention.

[0034] FIGS. 2 and 3 depict first steps in the fabrication of a P 2 pole tip of the magnetic head 20 of the present invention, wherein FIG. 2 is a top plan view and FIG. 3 is a side cross-sectional view taken along lines 3 - 3 of FIG. 2 . As depicted in FIGS. 2 and 3 , the fabrication process of a magnetic head upon a wafer substrate surface has been conducted to the point of the fabrication of a first pole (P 1 ) 30 upon an insulation layer (not shown) followed by the deposition of a write gap layer 34 upon the P 1 pole 30 . As indicated above, the fabrication of magnetic heads to this point is well known to those skilled in the art. Following the deposition of the write gap layer 34 , a block of nonconductive material 40 is fabricated upon the write gap layer. The block of material 40 can be fabricated in a variety of ways, such as by depositing a photoresist and photolithographically patterning and removing portions of the photoresist such that the block of material remains. The significant features of the block of material are that its height h should correspond to the height of the desired P 2 pole tip, that its thickness t corresponds to the desired thickness of the P 2 pole tip, that the block 40 be positioned such that its sidewall 44 be accurately located above the P 1 pole at the desired location of the P 2 pole tip, and that the sidewall 44 be smooth and vertical. Thereafter, as is depicted in FIGS. 2 and 3 , a seed layer 50 for the electroplating of the P 2 pole tip is deposited across the surface of the wafer, significantly including a seed layer portion 54 that is deposited to cover the sidewall 44 . The seed layer 50 is preferably composed of the same material as the pole tip, such as NiFe, and is deposited using a typical sputter deposition technique.

[0035] A further step in the fabrication of the magnetic head of the present invention is depicted in FIGS. 4 and 5 , wherein FIG. 4 is a top plan view and FIG. 5 is a side cross-sectional view taken along lines 5 - 5 of FIG. 4 . As depicted in FIGS. 4 and 5 , following the deposition of the seed layer, a photoresist layer 60 is deposited on top of the seed layer 50 and across the surface of the wafer. Thereafter, utilizing photolithographic techniques, a P 2 pole tip trench 64 is photolithographically formed in the photoresist layer 60 . Significantly, the P 2 pole tip trench is located to expose the seed layer 54 deposited upon the sidewall 44 . The width r of the P 2 pole tip trench 64 is chosen to be sufficiently wide to allow unimpeded electroplating of the P 2 pole tip within the trench 64 as is next described with the aid of FIGS. 6 and 7 , wherein FIG. 6 is a top plan view of the electroplating step and FIG. 7 is a side cross-sectional view taken along lines 7 - 7 of FIG. 6 .

[0036] As depicted in FIGS. 6 and 7 , the P 2 pole tip material 70 is next electroplated onto the exposed seed layer 50 utilizing standard electroplating techniques as are known to those skilled in the art. It is significant that the P 2 pole tip material 70 is electroplated outward from the seed layer portion 54 deposited upon the sidewall 44 . That is, the critical width dimension of the P 2 pole tip is now determined by the electroplating parameters related to the thickness of the electroplated layer as is further described hereinbelow. Thus the width of the P 2 pole tip is not determined by the width of the P 2 pole tip trench, as is done in the prior art. As a result, the prior art problems associated with limits upon the aspect ratio of the P 2 pole tip trench in the photolithographic process are no longer significant.

[0037] Following the electroplating step, the photoresist 60 is removed, preferably using a wet chemical process, and FIG. 8 is a top plan view depicting the device following photoresist removal and FIG. 9 is a side cross-sectional view taken along lines 9 - 9 of FIG. 8 that likewise depicts the device following the removal of the photoresist. In a following step, as depicted in FIGS. 8 and 9 the seed layer 50 is removed preferably utilizing an ion beam milling step, typically utilizing argon, as is known to those skilled in the art. FIG. 10 is a top plan view of the device following the removal of the seed layer and FIG. 11 is a side cross-sectional view taken along lines 11 - 11 of FIG. 10 , depicting the device following the removal of the seed layer in the ion milling step. With reference to FIGS. 8, 9 , 10 and 11 , and as can be particularly seen by comparing FIGS. 9 and 11 , the ion milling step is conducted for a sufficient time period to remove the upper, overlaid portion 74 of the electroplated pole tip material and the lower overlaid portion 78 of the P 2 pole tip material, such that the remaining portion of the P 2 pole tip 80 includes portions of the seed layer 54 deposited upon the sidewall 44 and the P 2 pole tip material 88 that has been electroplated onto the seed layer 54 . Thereafter, as depicted in FIGS. 10 and 11 , the resist block 40 is removed in a further wet chemical process, such that only the P 2 pole tip structure 80 remains on the write gap surface 34 . It can now be clearly seen that the width W of the P 2 pole tip 80 is comprised of the thickness of the seed layer 54 deposited upon the sidewall 44 plus the thickness of the pole tip material 88 electroplated onto the sidewall seed layer 54 . Furthermore, as indicated above, the width W of the P 2 pole tip has been determined in the electroplating process by selection of appropriate electroplating process parameters rather than by the width of the P 2 pole tip plating trench 64 .

[0038] With the P 2 pole tip 80 fabricated on the wafer surface, as depicted in FIGS. 10 and 11 , a P 1 notching process can now be advantageously conducted. As will be understood by those skilled in the art, a patterned ion etching mask is fabricated upon the wafer substrate such that the P 2 pole tip 80 and portions of the write gap layer adjacent thereto are exposed to an ion milling beam. As depicted in FIGS. 10 and 11 , the ion milling is conducted to remove portions of the write gap layer 34 adjacent to the P 2 pole tip 80 and to mill a notch 92 into the P 1 pole 30 . As is known to those skilled in the art, P 1 pole notching advantageously reduces side writing effects of a magnetic head. Where P 1 pole notching is not desired, the block of material 40 can be allowed to remain on the write gap layer 34 to support the P 2 pole tip 80 , and the fabrication of the induction coil (as is next described) can be commenced.

[0039] As is next depicted in FIGS. 12 through 16 , further fabrication steps, as are known to those skilled in the art, are next conducted to complete the fabrication of the magnetic head. Thus, as depicted in FIGS. 12 and 13 , wherein FIG. 12 is a top plan view of the head, and FIG. 13 is a side cross-sectional view taken along lines 13 - 13 of FIG. 12 , an induction coil is fabricated upon the wafer surface by photolithographic techniques to create an induction coil trench 100 within an insulation layer 104 , followed by electroplating techniques to electroplate the induction coil 108 , typically composed of copper, into the induction coil trench 100 . Therefore, as depicted in FIG. 12 , the induction coil trench is located immediately above the previously fabricated P 2 pole tip 80 . Alternatively, as is known to those skilled in the art, the induction coil can be fabricated utilizing a suitable dielectric material layer and a reactive ion etching process to create the induction coil trench, followed by the electroplating of the induction coil therewithin. As is next depicted in FIG. 14, a chemical mechanical polishing (CMP) step is conducted to remove any excess induction coil material and to achieve a planar surface 112 upon the wafer. Thereafter, a patterned insulation layer 116 is deposited on top of the induction coil. Significantly, the insulation layer 116 is not deposited upon the top surface of the P 2 pole tip 80 . As is next depicted in FIG. 15, a further magnetic pole piece 120 (sometimes referred to as a P 2 pole yoke or a P 3 pole) is fabricated upon the surface of the insulation layer and in magnetic connection with the P 2 pole tip 80 . The P 3 pole 120 is preferably fabricated utilizing photolithographic techniques and electroplating techniques as are well known to those skilled in the art. As depicted in FIG. 15 , the P 3 pole is preferably fabricated upon the P 2 pole tip, such that a gap 124 is provided between the end surface 128 of the P 3 pole and the end surface 132 of the P 2 pole tip 80 . When the wafer level fabrication steps are completed, the wafer is sliced to create rows of magnetic heads. As depicted in FIG. 16 , the air bearing surface (ABS) 148 is then fabricated, such that the gap 124 remains. Thereafter, further magnetic head fabrication steps are conducted, as are well known to those skilled in the art, and encapsulation layer 140 is ultimately fabricated upon the device. Further fabrication steps as are well known to those skilled in the art are then undertaken to complete the fabrication of the magnetic head 20 of the present invention.

[0040] It is therefore to be understood that a significant feature of the present invention is that the width W of the P 2 pole tip 80 is determined in the electroplating process steps by the deposition of P 2 pole tip material 88 upon the sidewall seed layer 54 . Thus, through the present invention, a P 2 pole tip 80 is fabricated wherein the width W is determined by the thickness of the sidewall seed layer 54 plus the thickness of the electroplated material 88 layer thereon. For example, a P 2 pole tip 80 of the present invention may be fabricated wherein the sidewall seed layer thickness is approximately 50 Å to 500 Å and the electroplated material thickness is approximately 100 Å to 5000 Å, such that the P 2 pole tip width W is approximately 150 Å to 5500 Å. In the preferred embodiment the seed layer thickness is approximately 250 Å and the electroplated material thickness is approximately 1500 Å, such that the width W of the P 2 pole tip is approximately 1750 Å. The thickness dimension t of the P 2 pole tip 80 is controlled by the thickness t of the deposited sidewall, less material removed from the top of the P 2 pole tip during P 1 pole notching, if conducted. Thus, as will be understood by those skilled in the art, the width W of the P 2 pole tip 80 of the present invention is now within the control of the magnetic head electroplating step, and not controlled by the photolithographic aspect ratio problems encountered in the prior art. Thus the prior art P 2 pole tip fabrication problems associated with the aspect ratio of the photolithographically created P 2 pole tip trench are overcome.

[0041] While the present invention has been shown and described with regard to certain preferred embodiments, it will be understood that those skilled in the art will no doubt develop certain alterations and modifications and form and detail. It is therefore intended that the following claims cover all such alterations and modifications that nevertheless include the true spirit and scope of the present invention.