JPH02214009A - Magneto-resistance effect type head - Google Patents

Abstract

PURPOSE:To obtain the head which does not decrease reproduced output when a track width is narrowed by increasing the specific resistance in a magneto- resistance effect element larger the farther from a sliding surface and setting the taper of current wire only partly near the sliding surface. CONSTITUTION:The specific resistance in the part of the magneto-resistance effect element 1 irradiated with inert gaseous ions, such as Ar ions or metal ions, etc., is increased without changing the magnetic resistance of this part when the above-mentioned element is partly irradiated with the above-mentioned ions. The current density of the detecting current I flowing in the magneto- resistance effect element 1 is increased nearer the sliding surface without changing the electric resistance over the entire part of the magneto-resistance effect element 1 so much by controlling the region to be irradiated with the ions. The flow of the detecting current to the boundary region of the electric resistance effect element 1 of the magneto-resistance effect element 1 and the current wires 2 is possible as well by providing the taper to a part of the current wires 2 and, therefore, the effective track width as the head is narrowed to the spacing between a pair of the current wires.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a magnetoresistive head for achieving high-density magnetic recording, and particularly to a magnetoresistive head with a very narrow track width of around 1 μm. Regarding.

[Conventional technology]

A perspective view of a conventional magnetoresistive head is shown in FIG.
A known example of a magnetoresistive head in which the pair of current lines 22 for supplying the detection current I to the magnetoresistive element 11 is tapered to increase the current density in a region close to the medium. is 1, for example, JP-A-6
No. 0-234213.

[7111M to be Solved by the Invention] However, in the above-mentioned known example in which the current line is tapered over the entire height of the magnetoresistive element, the signal detection section, that is, the magnetoresistive element sandwiched between the pair of current lines. The electrical resistance R increases. The reproduction output of a magnetoresistive head is proportional to ΔR/H, where ΔR is the resistance change when a signal is applied, so in this case, even if the resistance change ΔR is increased, k also increases, so the reproduction output is cannot be improved,
Further, the magnetoresistive head shown in the known example is essentially not suitable for narrow track heads because ΔR/R tends to decrease as the track width becomes narrower.

An object of the present invention is to provide a magnetoresistive head that does not cause a decrease in reproduction output when the track width is narrowed.

[Means to solve the problem]

The above purpose is to increase the specific resistance within the magnetoresistive element as it moves away from the sliding surface, and/or
This is achieved by providing the current line with a taper only in a portion near the sliding surface.

[Effect]

By irradiating a part of the magnetoresistive element with an inert ion gas such as Ar ions, or metal ions, it is possible to increase the specific resistance without changing the magnetoresistance of the irradiated part. By controlling the area to which these ions are irradiated, it is possible to increase the current density of the detection current flowing within the magnetoresistive element as it approaches the sliding surface, without significantly changing the electrical resistance of the entire magnetoresistive element. becomes.

In addition, by providing a taper in a portion of the current line (near the sliding surface), the edge portion of the signal detection area can be removed without increasing the electrical resistance of the magnetoresistive element.

In other words, it is possible to flow the detection current even in the boundary area between the magnetoresistive element and the current line on the sliding surface, making it possible to narrow the effective track width of the head to the distance between a pair of current lines. .

〔Example〕

The present invention will be explained in detail below. First, FIG. 1 shows a perspective view of a magnetoresistive head according to an embodiment of the present invention. The magnetoresistive element l in FIG. um, and the height is 5 μm. Reference numeral 2 denotes a current line for supplying a detection current to the magnetoresistive element 1, and is made of Ti. Note that in FIG. 1, current lines and the like for applying a bias magnetic field to the magnetoresistive element are omitted. The reason why Ti is used for the current wire is that since the current wire is exposed on the sliding surface, it is necessary to use a material with excellent corrosion resistance.

If the current line 2 is not exposed to the sliding surface, metals with low resistivity such as Cu and Mo can also be used. 3 indicates a region into which inert ions or metal ions are implanted.

Figure 3 shows a prototype head in which the resistivity was partially increased by implanting Ar ions into a part of the magnetoresistive element with a thickness of 400 mm, a width of 10.0 μm, and a height of 5 μm. This is the result of examining the effects of ion implantation. The track width of the head used here was 1'w, that is, the distance between the pair of current lines was 10 μm. 81! Specifically, a γFezes coating medium with a film thickness of 0.4 μm and a coercive force of 4000 e was used, and the spacing with the head was set to 0.2 μm.

For recording, track width is 20 μm, gap length is 0.4
There was a pm Metal In Gap mill head. Ar
The ion implantation conditions were an accelerating voltage of 15 keV, a dose of I x 10 "1 ons/m", and a specific resistance of permalloy, which is a magnetoresistive element using a cocote, of 2.
The specific resistance of the region into which Ar ions were implanted increased to 60 μΩ·l.

The horizontal axis in Figure 3 is the ratio yt/y of the magnetoresistive element height y and the distance yi from the sliding surface to the ion implanted area, and the vertical axis is the peak value of the reproduction output at 5 kF' CI. This is a standardized value. From this result, the reproduction output is maximized when ions are implanted in a region about half the height y of the magnetoresistive element from the sliding surface.

This value is approximately 1.7 when not entered (y+/y=1)
It can be seen that this is doubled. It has been confirmed that almost the same effect can be obtained by using metal ions such as He ions, Ni ions, F''a ions, etc. in addition to Ar ions as ions implanted into a part of the aI magnetoresistive element.

Next, we produced a prototype head with a track width narrowed to 2 μm and measured the changes in the reproduction output. The results of the measurements are shown in Figure 4. The shape of the magnetoresistive effect element used here was 1100 μm in length and 5 μm in height.
m, thickness 400 people, the same as that used for the measurements in FIG. Further, Ar ions are implanted in a region more than half the height of the magnetoresistive element from the sliding surface. The vertical axis in FIG. 4 is the reproduction output per unit track width at 5 kPCI normalized by the peak value, and the horizontal axis is the track width, that is, the distance between a pair of current lines. This result shows that in a head where the pair of current lines are parallel to each other.

Even if the specific resistance is changed by implanting ions, the reproduction output gradually decreases when the track width is narrowed below 8 μm, and the change in reproduction output with respect to the track width shows the same tendency as a head without ion implantation. I understand that. The reason for this is that it is difficult for the detection current to flow in the edge part of the fa magnetoresistive element signal detection area, that is, in the boundary area between the magnetoresistive element and the current line on the sliding surface, and as the track width is narrowed, This is thought to be because the ratio of this area to the track width increases, thereby narrowing the effective track width.

Next, Figure 5 shows the effect of improving the reproduction output by providing a taper in a part of the current line.The prototype head used in this experiment had a length of 100 μm, a height of 5 μm, and a thickness of 400 mm. The track width Tw was set to 2 μm, and the taper angle θ of the current line was set to 45°. Further, FIG. 5, in which ions are implanted in a region more than half the height of the magnetoresistive element from the sliding surface, is the result of measuring the relationship between the position at which the taper begins and the reproduction output.

The vertical axis in Figure 5 is the value normalized to the peak value of the reproduction output at 5kPCI, and the horizontal axis is the distance fily' from the sliding surface to the position where the current line starts to taper with respect to the magnetoresistive element height y. The ratio is y'/y.

From this result, the regeneration is maximized by setting the distance y' from the sliding surface to the point where the current line starts to taper to around 30% of the height of the magnetoresistive element, and when the current lines are parallel. Approximately 2.5 times (y/y'=o), if the entire height of the magnetoresistive element is curved or tapered (y/y
' = 1). Note that the position at which the taper starts at which the reproduction output is maximum varies depending on the taper angle, track width, etc., and therefore needs to be determined after taking these values into consideration.

〔Effect of the invention〕

According to the present invention, it is possible to obtain a magnetoresistive head with high playback efficiency even when the track width is around 1 μm, so it is possible to obtain a separate recording/playback head for magnetic disk drives that have a large storage capacity and require high-speed data transfer. It is effective as a playback head.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of the main part of a magnetoresistive head according to an embodiment of the present invention, and FIG. 2 is a perspective view of the main part of a conventional magnetoresistive head. FIG. 3, FIG. 4, and FIG. 5 are diagrams for explaining the effect of improving reproduction output according to different embodiments of the present invention. 1.11...Magnetoresistive effect element, 2.22...Signal detection number, track and number Tw()Aweiji

Claims (1)

[Claims] 1. In a magnetoresistive head in which a track width is defined by the interval between a pair of current lines provided for supplying current for signal detection to the magnetoresistive element, the magnetoresistive element described above A magnetoresistive head characterized in that the specific resistance within the head is not uniform, and that the specific resistance in a region away from the sliding surface with the recording medium is large. 2. In the magnetoresistive head according to claim 1, inert gas ions such as Ar ions and He ions, or Ni ions and Fe ions are provided in a region of the magnetoresistive element away from the sliding surface. A magnetoresistive head characterized by increasing the specific resistance without changing the magnetic properties of this part by implanting metal ions such as. 3. In the magnetoresistive head according to claim 2, the ions are implanted into a region that is more than half the height of the magnetoresistive element from the sliding surface of the magnetoresistive element. Features a magnetoresistive head. 4. A magnetoresistive head according to claim 1, wherein a portion of the pair of current lines is tapered. 5. A magnetoresistive element cut into a rectangular shape and arranged with its surface substantially perpendicular to the surface of the recording medium and its long side substantially perpendicular to the traveling direction of the recording medium, and a signal detection current applied to the magnetoresistive element. In a magnetoresistive head having a pair of current lines for supplying current, the ends of the current lines are shaped so that the distance between the ends is minimized on the long side of the magnetoresistive element on the recording medium side. and wherein the end portion has a side perpendicular to the recording medium and the spacing thereof remains constant up to a certain distance from the long side of the magnetoresistive element opposite to the recording medium. Magnetoresistive head.