JPH07280905A - Magnetic sensor - Google Patents

Abstract

PURPOSE:To provide a magnetic sensor whose detection sensitivity is good, in which heat generated by an exciting coil is small and in which thin films are integrated. CONSTITUTION:A coil wiring part 3 formed out of copper Cu is laminated, via an intermediate layer 2 formed out of aluminum Al, on a substrate 1 formed out of silicon dioxide SiO2. In addition, an insulating layer 5 formed out of silicon oxide SiO is laminated on the coil wiring part 3 via an intermediate layer 4 which is formed out of aluminum Al and alumina Al2O3. As a result, the coil wiring part 3 is laminated with a good contact property with reference to the substrate 1 and the insulating layer 5 via an aluminum compound whose close adhesion with copper Cu and a silicon oxide is good.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic sensor used to measure, for example, geomagnetism.

[0002]

2. Description of the Related Art Recently, a thin film integrated magnetic sensor has been developed in order to miniaturize and mass produce a magnetic sensor for measuring an external magnetic field such as geomagnetism. The gate type magnetic sensor is suitable for thin film integration.

FIG. 4 shows a principle diagram of this flux gate type magnetic sensor. The exciting coil 13a is supplied with an alternating current IEX sufficient for saturation magnetization of the ring core L, and points A and B are provided. Then, an AC magnetic flux φEX is generated via the ring core L. And the receiving coil 13b
Is the voltage v _A generated by the change in the magnetic flux φ _A at point _A.
And the voltage v _B generated by the change of the magnetic flux φ _{B at} the point _B are added so that they can be detected. Therefore, in such a configuration, when the external magnetic field H is not present, the magnetic fluxes φ _A and φ _{B at the} points A and B are equal in magnitude to the magnetic flux φ _EX and have opposite bendability.
Although no signal voltage appears at 3b, when an external magnetic field H exists, an imbalance of magnetic flux occurs at points A and B, and a signal voltage appears at the receiving coil 13b. By analyzing this, the external magnetic field H can be measured. Becomes

In the conventional thin film integrated flux gate type magnetic sensor, the coil wiring portion including the receiving coil and the exciting coil is used as an insulating layer.
silicon oxide and adhesion, such as i0 and Si0 ₂ was formed with good aluminum Al.

[0005]

However, since aluminum Al has a large resistance value, if it is used for the coil wiring portion, the detection sensitivity is deteriorated, and heat generation of the exciting coil adversely affects the detection result. There was a problem.

On the other hand, the coil wiring portion is made of copper Cu having a low resistance value.
If it is formed by (1), the adhesion with silicon oxide is poor, so that its lamination becomes difficult.

Further, it is a well-known fact that chromium Cr is laminated between copper Cu and silicon oxide to enhance the adhesion between them, but it is a ferromagnetic material such as chromium C.
It is impossible to use r for a magnetic sensor.

The present invention was conceived to solve the above problems, and an object of the present invention is to provide a thin film integrated magnetic sensor which has good detection sensitivity and has less heat generation in the excitation coil.

[0009]

In order to achieve the above object, the present invention provides a thin film integrated magnetic sensor for detecting an external magnetic field by a coil wiring portion laminated via an insulating layer made of silicon oxide. In the above, the coil wiring portion is formed of copper, and an aluminum compound is interposed between the insulating layer and the coil wiring portion.

[0010]

The operation of the present invention will be described with reference to FIG. 3. A coil wiring portion 3 made of copper Cu is laminated on a substrate 1 made of silicon dioxide SiO2 with an intermediate layer 2 made of aluminum Al interposed therebetween. Further, an insulating layer 5 made of silicon oxide SiO is formed on the coil wiring portion 3 via an intermediate layer 4 made of aluminum Al and alumina Al ₂ O _3.
Since the coil wiring portion 3 formed of copper Cu is
It is laminated on the substrate 1 and the insulating layer 5 with good adhesion via copper Al and aluminum Al having good adhesion with silicon oxide. Therefore, in the thin film integrated magnetic sensor, it is possible to use copper Cu having a low resistance for the coil wiring portion 3, the detection sensitivity of the external magnetic field is improved, and the adverse effect on the detection result due to the heat generation of the excitation coil is significant. Decrease to.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. 1 and 2 show a circuit pattern of a flux gate type magnetic sensor suitable for miniaturization of a magnetic sensor in the process of thin film integration of a coil wiring portion such as a receiving coil and an exciting coil. First, as shown in FIG. 1, an L-shaped excitation line 3a ′ for forming an excitation coil and a signal line 3b ′ for forming a reception coil are formed on the substrate 1 in the first wiring layer. In FIG. 1, the ring cores L (FIG. 2) (not shown) are formed at predetermined intervals along the circumference corresponding to the region where they are formed. Then, as shown in FIG. 2, the second wiring layer is formed by laminating an insulating layer and a ring core L on the first wiring layer formed by the excitation line 3a ′ and the signal line 3b ′, and further by insulating layer This second wiring layer has an L-shaped direction opposite to that of each line 3a ′ and 3b ′ of the first wiring layer shown in FIG.
Excitation lines 3a ″ formed at positions opposing the respective lines 3a ′ and 3b ′ of the first wiring layer with the ring core L interposed therebetween.
And the signal line 3b ″, and the excitation line 3a ″ and the signal line 3
It consists of extraction electrodes 11 and 10 of b ″.

Here, the excitation line 3a 'of the first wiring layer, the excitation line 3a "of the second wiring layer, and the signal line 3 of the first wiring layer.
b ′ and the signal line 3b ″ of the second wiring layer are contact holes (not shown) for winding the ring cores L formed by laminating between the first wiring layer and the second wiring layer, respectively. The excitation line 3a ′ of the first wiring layer, the excitation line 3a ″ of the second wiring layer, and the connection line in the contact hole form the excitation coil, and similarly the first wiring. A receiving coil is formed by the signal line 3b ′ of the layer, the signal line 3b ″ of the second wiring layer, and the connection line in the contact hole, respectively, and the same structure as the fluxgate magnetic sensor shown in the principle diagram of FIG. Is realized.

Next, in the thin-film integrated magnetic sensor having the above-mentioned structure, the above-mentioned excitation lines 3a ', 3
A case in which the coil wiring parts such as a ″, the signal lines 3b ′ and 3b ″, and the extraction electrodes 10 and 11 are laminated on the substrate 1 will be described. FIG. 3 shows one cross-sectional view including the coil wiring portion of the first wiring layer or the second wiring layer described above,
For example, if this sectional view is taken as a sectional view of the first wiring layer,
A layer on which the ring core L is formed, an insulating layer for insulating the second wiring layer from the ring core L, a second wiring layer, and the like are stacked on the insulating layer 5.

As shown in the figure, the wiring layer is
An intermediate layer 2 is laminated on the substrate 1 made of silicon dioxide SiO ₂ by vapor deposition of aluminum Al to a thickness of about 50 nm by sputtering or the like, and copper Cu of 2 μm is deposited thereon.
After stacking the coil wiring layers 3 formed by vapor deposition, aluminum Al and alumina Al are formed on the coil wiring layers 3.
It is formed by stacking an intermediate layer 4 made of ₂ O ₃ and further stacking an insulating layer 5 made of silicon oxide Si0 on the intermediate layer 4. Then, a circuit pattern such as another coil wiring layer is further laminated on the insulating layer 5. Here, the intermediate layer 4 has a two-layer structure in which aluminum Al is vapor-deposited to a thickness of about 100 nm by sputtering or the like, and is then oxidized by the anode electrode method to form alumina Al ₂ O ₃ having a thickness of about 50 nm. The insulating property with respect to the coil wiring portion and the like, which are further laminated via 5, is further improved, and the detection sensitivity of the external magnetic field and the like are further improved.

Although the substrate 1 is formed of silicon dioxide SiO ₂ and the insulating layer 5 is formed of silicon oxide SiO in the above-described embodiment, the present invention is not limited to this and is generally represented by SiO _x. Any silicon oxide may be used. Further, the intermediate layers 2 and 4 are formed of aluminum Al or alumina Al ₂ O ₃ , but the present invention is not limited to this, and any aluminum compound containing aluminum such as Al _X O _Y may be used. For example, elements that form an alloy with aluminum include B, C, Nb, Ga, and G.
e, Hf, Li, Mg, Mn, Pn, Sb, Ta, T
i, U, V, W, Zn, Zr, Cu, Si and the like are considered.

As described above, according to the present invention, since the coil wiring portion 3 formed of copper Cu is laminated with copper Cu and the silicon oxide SiO _x via the aluminum compound having good adhesion, The coil wiring portion 3 made of copper Cu and the insulating layer 5 made of silicon oxide SiO _x are laminated together with good adhesion. Therefore, in a thin film integrated magnetic sensor, low resistance copper Cu is used in the coil wiring portion.
Can be used, the sensitivity of detecting the external magnetic field can be improved, and the adverse effect on the detection result due to heat generation of the excitation coil can be significantly reduced.

[0017]

According to the magnetic sensor of the present invention, since the coil wiring portion formed of copper Cu is laminated with copper Cu and the silicon oxide SiO _x via an aluminum compound having good adhesion, a thin film is formed. In the integrated magnetic sensor, it is possible to use copper Cu having a low resistance in the coil wiring portion, the detection sensitivity of the external magnetic field is improved, and the adverse effect on the detection result due to heat generation of the excitation coil is significantly reduced.

[Brief description of drawings]

FIG. 1 is a diagram showing a circuit pattern of a coil wiring portion of a first layer of a fluxgate type magnetic sensor.

FIG. 2 is a diagram showing a circuit pattern of a coil wiring portion of a second layer of a flux gate type magnetic sensor.

FIG. 3 is a cross-sectional view of a coil wiring portion in which a thin film is integrated according to the present invention.

FIG. 4 is a configuration diagram of a flux gate type magnetic sensor.

Claims (1)

[Claims] 1. A magnetic sensor integrated with a thin film, which detects an external magnetic field by a coil wiring portion laminated via an insulating layer made of silicon oxide, wherein the coil wiring portion is formed of copper and the insulation is formed. A magnetic sensor comprising an aluminum compound interposed between a layer and the coil wiring portion.