JPH0484472A - Manufacture of magnetoresistance element - Google Patents

Abstract

PURPOSE:To reduce the number of types of masks and decrease variations in resistance patterns due to the influence caused by misregistration of upper and lower masks in the adjacent film by using one type of mask and comprising a step of removing two types of unnecessary films. CONSTITUTION:After a basement oxide silicon 2, a permalloy 3, gold 4, titanium 5 are formed on a silicon substrate 1, a resist film 6 is formed (a). Next, after patterning is performed, a resist film is peeled after unwanted portions are removed by dry etching (b). Next, after a resist film 7 is formed and patterned, titanium 5 in a sensor portion B is removed by dry etching (c), and the resist film 7 is peeled by wet etching after gold 4 in the sensor portion B is removed (d). Next, cover oxide silicon 10 is formed in an MR element (e). Next, after a resist film 8 is formed, patterning is performed. Thereafter, cover oxide silicon 10 in electrode portions A, A' is etched by wet etching (f). At the same time, titanium 5 in the electrode portions A, A' is removed by etching (g), and thereafter the resist film 8 is peeled (h).

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to magnetoresistive (MR)
The present invention relates to a method of manufacturing an istive device, and particularly to a method of forming a resistive pattern including an electrode portion and a sensor portion.

[Conventional technology]

A conventional method for manufacturing an MR element will be explained with reference to FIG.

First, as shown in FIG. 2(a), a base silicon oxide layer 2 is placed on a silicon substrate 1. Permalloy 3. After forming the gold 4 titanium 5, a resist film 6 is formed.

Next, as shown in FIG. 2(b), after patterning,
After dry etching (ion milling) removes unnecessary portions of the titanium 5 on the electrode parts A, A' and the sensor part B, the resist film 6 is peeled off.

Next, as shown in FIG. 2(C), after forming and patterning a resist film 7, unnecessary portions of the permalloy 3. After deleting gold 4 and titanium 5,
The resist M7 is peeled off.

Next, as shown in FIG. 2(d), after forming and patterning a resist film 8, the gold 4 on the sensor part B is removed by wet etching (potassium iodide solution, etc.), and then the resist film 8 is removed. Peel off.

Next, as shown in FIG. 2(e), a cover silicon oxide 10 is formed on the MR element.

Next, as shown in FIG. 2(f), after forming a resist film 9, patterning is performed, and after etching the cover silicon oxide 1o by wet etching, as shown in FIG. 2(g), The resist film 9 is peeled off.

In this way, in the conventional manufacturing method, a necessary mask is created for each film formed on a silicon substrate l, and after patterning, dry etching (ion milling) or wet etching (potassium iodide solution, etc.) is used to pattern the desired part. The unnecessary film is removed to form a resistor pattern.

[Problem to be solved by the invention]

In conventional MR element manufacturing methods, unnecessary films in arbitrary parts can be removed by creating a mask for each film being formed and then patterning and dry etching or wet etching. In the case of the sensor section, if there is a misalignment between the titanium etching mask (resist film 6) and the gold etching mask (resist film 8), the resistance variation will increase and it will be difficult to obtain a desired resistance value. , there was a problem that the blower yield decreased.

An object of the present invention is to provide a method for manufacturing a magnetoresistive element that solves these problems.

[Means to solve the problem]

The present invention is a method for manufacturing a magnetoresistive element, characterized in that it includes a step of removing two types of unnecessary films using one type of mask.

The present invention also provides a method for manufacturing a magnetoresistive element in which base silicon oxide, permalloy, gold, titanium, and cover silicon oxide are laminated on a silicon substrate. The feature is that the cover silicon oxide is removed and the gold and titanium on the permalloy of the sensor section are removed by patterning using one type of mask and dry etching and wet etching to form a resistance pattern.

The present invention also includes a step of laminating a base oxidized silicone, permalloy, gold, titanium, and a cover silicon oxide on a silicon substrate, and after forming and patterning a resist film, the sensor portion is etched by dry etching. A process of removing titanium from the electrode area, followed by removing gold by wet etching, and a process of forming a resist film and patterning it, removing silicon oxide covering the electrode part by wet etching, and then removing titanium by dry etching. It is characterized by including.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIGS. 1(a) to 1(h) are line sectional views of an MR element shown in order of steps for explaining one embodiment of the present invention.

First, as shown in FIG. 1(a), a base silicon oxide layer 2 is placed on a silicon substrate 1. Permalloy 3. After forming the gold 4° titanium 5, a resist film 6 is formed.

Next, as shown in FIG. 1(b), after patterning,
Dry etching (ion milling) removes unnecessary parts of permalloy between sensor part B and electrode parts A and A'.3. After removing gold 4 and titanium 5, resist film 6 is peeled off.

Next, as shown in FIG. 1(C), after forming and patterning a resist film 7, the titanium 5 of the sensor part B is removed by dry etching (reactive etching), and then as shown in FIG. 1(d). As shown, after removing gold 4 on sensor part B by wet etching (potassium iodide solution, etc.),
The resist film 7 is peeled off. In this way, one type of mask (
Two types of unnecessary films (titanium 5 and gold 4) can be removed using the resist film 7).

Next, as shown in FIG. 1(e), a cover silicon oxide 10 is formed on the MR element.

Next, as shown in FIG. 1(f), after forming a resist film 8, patterning is performed, and then wet etching (buffered hydrofluoric acid) is performed to cover the silicon oxide 10 of the electrode parts A and A'. etching.

At the same time, as shown in FIG. 1(g), the titanium 5 on the electrode parts A and A' is removed by dry etching, and then the resist film 8 is peeled off as shown in FIG. 1(h). do. In this way, one type of mask (resist film 8) removes two types of unnecessary films (cover silicon oxide 10).
and titanium 5) can be deleted.

As explained above, by changing the manufacturing process, the method for manufacturing an MR element of the present invention is different from the conventional method of forming and using a mask for each film to be formed and removing unnecessary films. Rather, it attempts to remove two types of unnecessary films by dry etching and wet etching in one patterning process using one type of mask.

[Effects of the Invention] As explained above, the present invention makes it possible to remove two types of films in any part by patterning with one type of mask, thereby reducing the number of types of masks and removing the upper and lower portions of adjacent films. Since the variation in the resistance pattern due to the influence of mask position shift is extremely small, it is possible to manufacture a highly accurate resistance pattern for the MR element.

[Brief explanation of drawings]

1(a) to (h) are longitudinal sectional views of an MR element shown in the order of steps for explaining one embodiment of the present invention, and FIGS. 2(a) to 2(h)
(g) is a vertical cross-sectional view of an MR element shown in the order of steps for explaining a conventional example. 1...Silicon substrate 2...Silicon oxide base 3...Permalloy 4...Gold 5...Titanium 6...Resist film (first 7...Resist film (for 2nd patterning) 8...Resist film (for 3rd patterning) 9...Resist film (for 4th patterning) IO ...Cover silicon oxide A...Electrode section A'...Electrode section B...Sensor section Fig. 1 Fig. 2

Claims (3)

[Claims] (1) A method for manufacturing a magnetoresistive element, the method comprising: using one type of mask and removing two types of unnecessary films. (2) In a method for manufacturing a magnetoresistive element in which base silicon oxide, permalloy, gold, titanium, and cover silicon oxide are laminated on a silicon substrate, titanium on the gold forming the electrode portion and the cover. A magnetoresistive element characterized in that the removal of silicon oxide and the removal of gold and titanium on the permalloy of the sensor part are performed by patterning using one type of mask, and by dry etching and wet etching to form a resistance pattern. Production method. (3) Layering base silicon oxide, permalloy, gold, titanium, and cover silicon oxide on a silicon substrate, forming a resist film and patterning, and then dry etching to remove titanium from the sensor area. and subsequently removing gold by wet etching, and after forming and patterning a resist film, removing silicon oxide covering the electrode part by wet etching, and then removing titanium by dry etching. A method for manufacturing a magnetoresistive element characterized by: