阅读说明：本技术 半导体装置 (Semiconductor device with a plurality of semiconductor chips ) 是由 飞冈孝明 上村纮崇 于 2019-07-03 设计创作，主要内容包括：本发明涉及半导体装置。是一种半导体装置,具有：第1导电型的半导体基板(10)；设置在半导体基板(10)上的纵向霍尔元件(100)；以及经由绝缘膜(30)设置在纵向霍尔元件(100)的正上方的、励磁导体(200),其中,纵向霍尔元件(100)具备：设置在半导体基板(10)上的、第2导电型的半导体层(101)；以及在半导体层(101)的表面在一条直线上设置的、由高浓度的第2导电型的杂质区域构成的多个电极(111)~(115),励磁导体(200)的宽度W<Sub>C</Sub>与电极(111)~(115)的宽度W<Sub>H</Sub>之比W<Sub>C</Sub>/W<Sub>H</Sub>为0.3≤W<Sub>C</Sub>/W<Sub>H</Sub>≤1.0。(The present invention relates to a semiconductor device. A semiconductor device includes: a semiconductor substrate (10) of a 1 st conductivity type; a longitudinal Hall element (100) provided on the semiconductor substrate (10); and an excitation conductor (200) provided directly above the longitudinal hall element (100) via an insulating film (30), wherein the longitudinal hall element (100) is provided with: a semiconductor layer (101) of the 2 nd conductivity type provided on the semiconductor substrate (10); and on the surface of the semiconductor layer (101) isA plurality of electrodes (111) ~ (115) formed of high-concentration impurity regions of the 2 nd conductivity type and arranged in straight lines, and the width W of the excitation conductor (200) C Width W of electrode (111) ~ (115) H Ratio W of C /W H W is not less than 0.3 C /W H ≤1.0。)

1. A semiconductor device includes:

a semiconductor substrate of a 1 st conductivity type;

a longitudinal hall element disposed on the semiconductor substrate; and

an excitation conductor provided directly above the longitudinal Hall element via an insulating film,

the semiconductor device is characterized in that it is provided with a plurality of semiconductor chips,

the vertical Hall element is provided with:

a semiconductor layer of a 2 nd conductivity type provided on the semiconductor substrate; and

a plurality of electrodes provided on a surface of the semiconductor layer in a straight line and each including a high-concentration impurity region of the 2 nd conductivity type,

width W of the excitation conductor_CWidth W of the electrode_HRatio W of_C/W_HW is not less than 0.3_C/W_H≤1.0。

2. The semiconductor device according to claim 1, wherein the excitation conductor is formed linearly, and a center line of the excitation conductor in a longitudinal direction thereof coincides with a center line of the semiconductor layer of the vertical hall element in the longitudinal direction thereof.

3. The semiconductor device according to claim 1 or 2, wherein, with respect to the excitation conductor, a distance h from a center of the longitudinal hall element in a substrate depth direction to the excitation conductor and a width W of the electrode_HRatio h/W_HIs 0.4 or less.

Technical Field

The present invention relates to a semiconductor device, and more particularly, to a semiconductor device including a vertical hall element for sensing a magnetic field in a horizontal direction.

Background

The hall element can be used as a magnetic sensor for position sensing or angle sensing in a non-contact manner, and is therefore used for various purposes. Among these, a magnetic sensor using a lateral hall element for detecting a magnetic field component perpendicular to the surface of a semiconductor substrate is generally known. Various magnetic sensors using a vertical hall element for detecting a magnetic field component parallel to the surface of the semiconductor substrate have been proposed. Further, a magnetic sensor has been proposed in which a lateral hall element and a longitudinal hall element are combined to detect a magnetic field in 2-and 3-dimensions.

However, the vertical hall element is more susceptible to the influence of the manufacturing variations in sensitivity and offset voltage characteristics than the horizontal hall element, and therefore, the characteristic variations are large.

In order to correct such characteristic variations, patent document 1 discloses the following method: the sensitivity of the hall element is estimated by causing a current to flow through an excitation conductor disposed in the vicinity of the vertical hall element, thereby generating a correction magnetic field having a predetermined magnetic flux density at the position of the hall element. That is, the actual sensitivity of the hall element is estimated by changing the magnetic flux density of the correction magnetic field and measuring the change in the hall voltage output from the hall element when the correction magnetic field is applied.

In fig. 1 of patent document 1, a structure is adopted in which the distance in the horizontal direction between the center of the excitation conductor and the center of the vertical hall element is increased, that is, the center of the excitation conductor and the center of the vertical hall element are shifted in the horizontal direction. Thus, it is intended to suppress the influence of the variation in the magnetic field intensity generated by the excitation conductor on the vertical hall element by using the variation in the width of the excitation conductor or the like due to the process variation in the manufacture of the semiconductor device.

Disclosure of Invention

Therefore, an object of the present invention is to provide a semiconductor device capable of suppressing the influence of heat generation of an excitation conductor on a peripheral circuit and increasing the intensity of a correction magnetic field received by a vertical hall element to thereby perform highly accurate correction of the vertical hall element.

Means for solving the problems

A semiconductor device according to an aspect of the present invention is a semiconductor device including: a semiconductor substrate of a 1 st conductivity type; a longitudinal hall element disposed on the semiconductor substrate; and an excitation conductor provided directly above the vertical hall element via an insulating film, the semiconductor device being characterized in that the vertical hall element includes: a semiconductor layer of a 2 nd conductivity type provided on the semiconductor substrate; and a plurality of electrodes arranged on a straight line on the surface of the semiconductor layer and composed of high-concentration impurity regions of the 2 nd conductivity type, wherein the width W of the excitation conductor_CWidth W of electrode of longitudinal Hall element_HRatio W of_C/W_HW is not less than 0.3_C/W_H≤1.0。

Effects of the invention

According to the present invention, the excitation conductor is disposed directly above the vertical hall element, and the width W of the excitation conductor is set to be equal to or greater than the width W of the longitudinal hall element_CWidth W of electrode of longitudinal Hall element_HRatio W of_C/W_HThe value of 1.0 or less makes it possible to arrange the peripheral circuits such as a circuit for processing an output signal from the vertical hall element and a circuit for supplying a signal to the vertical hall element so as not to be close to the excitation conductor, and to set W to be equal to or less than 1.0_C/W_HBy setting the temperature to 0.3 or more, an increase in the amount of heat generated by the excitation conductor can be suppressed, and therefore, the occurrence of temperature distribution in the peripheral circuit can be prevented. Further, by disposing the excitation conductor directly above the vertical hall element, the intensity of the correction magnetic field received by the vertical hall element can be increased. Therefore, the longitudinal hall element can be corrected with high accuracy by increasing the strength of the correction magnetic field applied to the longitudinal hall element while suppressing the amount of heat generation of the excitation conductor.

Drawings

Fig. 1 (a) is a plan view of a semiconductor device having a longitudinal hall element according to an embodiment of the present invention, and (b) is a sectional view taken along line L-L' of (a).

FIG. 2 is a view showing the distance h from the center of the longitudinal Hall element in the substrate depth direction to the excitation conductor and the width W of the longitudinal Hall element electrode_HRatio of (h/W)_H) Varies to the width W of the excitation conductor_CWidth W of electrode of longitudinal Hall element_HRatio of (W)_C/W_H) And a graph of the results obtained by simulating the relationship between the temperature rise of the excitation conductor when the excitation conductor generates a magnetic field having a magnetic flux density of 2 mT.

FIG. 3 is a view showing the distance h from the center of the longitudinal Hall element in the substrate depth direction to the excitation conductor 200 and the width W of the longitudinal Hall element electrode_HRatio of (h/W)_H) Varies to the width W of the excitation conductor_CWidth W of electrode of longitudinal Hall element_HRatio of (W)_C/W_H) And a graph of the results obtained by simulating the relationship between the magnetic flux density (B/I) applied to the longitudinal Hall element per unit current flowing through the excitation conductor.

Detailed Description

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings.

Fig. 1 is a diagram for explaining a semiconductor device having a vertical hall element according to an embodiment of the present invention, fig. 1 (a) is a plan view, and fig. 1 (b) is a cross-sectional view taken along line L-L' of fig. 1 (a).

As shown in fig. 1, the semiconductor device of the present embodiment includes: a P-type (1 st conductivity type) semiconductor substrate 10, a P-type element separation diffusion layer 20, a vertical hall element 100 provided on the semiconductor substrate 10, an insulating film 30 provided on the vertical hall element 100, and an excitation conductor 200 provided on the insulating film 30.

The vertical hall element 100 is configured to include: an N-type (2 nd conductivity type) semiconductor layer 101 serving as a magnetic sensing portion provided on a semiconductor substrate 10, and an electrode 111 composed of an N-type impurity region provided on a surface of the semiconductor layer 101 in a straight line~ 115 the electrode 111 ~ 115 is formed in a rectangular shape in plan view, and has the same width W_HAre respectively arranged in parallel.

The element isolation diffusion layer 20 electrically isolates the vertical hall element 100 from other regions (not shown) on the semiconductor substrate 10.

In other regions on the semiconductor substrate 10 electrically separated from the vertical hall elements 100 by the element separation diffusion layer 20, elements such as transistors constituting a circuit for processing an output signal from the vertical hall elements 100, a circuit for supplying a signal to the vertical hall elements 100, a circuit for compensating characteristics of the vertical hall elements 100 with a correction magnetic field, and the like (hereinafter, referred to as "peripheral circuits") are provided.

The excitation conductor 200 is formed linearly, and is provided directly above the hall element 100 via the insulating film 30 so that the center line of the excitation conductor 200 in the longitudinal direction coincides with the center line of the semiconductor layer (magnetic sensing portion) 101 of the hall element 100 in the longitudinal direction. This minimizes the distance between the excitation conductor 200 and the vertical hall element 100, increases the intensity of the correction magnetic field received by the vertical hall element 100, and supplies a uniform correction magnetic field to the entire vertical hall element 100.

Then, in the present embodiment, the width W of the excitation conductor 200 on the longitudinal hall element 100_CWidth W of the electrode 111 ~ 115 of the longitudinal hall element 100_HRatio W of_C/W_HW is more than or equal to 0.3_C/W_HThe relation of less than or equal to 1.0. The reason for adopting such a relationship will be described below.

When the correction magnetic field generated from the excitation conductor 200 and applied to the longitudinal hall element 100 becomes small, the change in the hall voltage output from the longitudinal hall element 100 becomes small, and therefore, the accuracy of estimating the actual sensitivity of the longitudinal hall element 100 is lowered, and therefore, it is preferable to apply 2 ~ 3mT or more to the correction magnetic field.

Therefore, fig. 2 shows the longitudinal hall and the distance h from the center of the longitudinal hall element 100 including the semiconductor layer 101 in the substrate depth direction to the excitation conductor 200Width W of electrode 111 ~ 115 of element 100_HRatio h/W_HChange to W_C/W_HA graph of the results obtained by simulating the relationship between the temperature rise of the excitation conductor 200 when the excitation conductor 200 generates a magnetic field having a magnetic flux density of 2mT_C/W_HIs the width W of the excitation conductor 200_CWidth W of the electrode 111 ~ 115 of the longitudinal hall element 100_HThe ratio of.

From the graph of fig. 2 it can be seen that: when width W of excitation conductor_CWidth W of electrode 111 ~ 115 of longitudinal hall element_HRatio W of_C/W_HWhen the temperature is 0.3 or less, the temperature rise of the excitation conductor 200 becomes large rapidly. Fig. 2 shows, as an example, a simulation result of the case where the excitation conductor 200 generates a magnetic field having a magnetic flux density of 2 mT. It was confirmed that: even in the case where the excitation conductor 200 generates a magnetic field having a magnetic flux density of 3mT or more, the shape of the graph is the same when W is_C/W_HWhen the temperature is 0.3 or less, the temperature rise of the excitation conductor 200 becomes large rapidly.

Therefore, by setting the width W of the excitation conductor_CWidth W of electrode 111 ~ 115 of longitudinal hall element_HRatio W of_C/W_HBy setting the temperature to 0.3 or more, it is possible to suppress the occurrence of temperature distribution in the peripheral circuit when the correction magnetic field of 2 ~ 3mT or more is applied to the longitudinal hall element 100 by applying the current to the excitation conductor 200.

On the other hand, when the width W of the excitation conductor 200_CIs wider than the width W of the electrode 111 ~ 115 of the longitudinal Hall element 100_HWhen large, the peripheral circuit is close to the excitation conductor 200. That is, the peripheral circuit is susceptible to the heat generated from the excitation conductor 200, and the accuracy of estimating the actual characteristics of the vertical hall element 100 is reduced. Therefore, in order to prevent the excitation conductor 200 from approaching the peripheral circuit, the width W of the excitation conductor 200 is preferably set_CNot larger than the width of the electrode 111 ~ 115 of the longitudinal Hall element 100, i.e. the width W of the excitation conductor_CWidth W of electrode 111 ~ 115 of longitudinal hall element_HRatio W of_C/W_HIs 1.0 or less.

FIG. 3 is a view showing the relationship between the distance h from the center of the longitudinal Hall element 100 in the substrate depth direction to the excitation conductor 200 and the width W of the electrode 111 ~ 115 of the longitudinal Hall element 100_HRatio h/W_HChange to W_C/W_HA graph of the results obtained by simulation of the relationship with the magnetic flux density (B/I) applied to the longitudinal hall element 100 per unit current flowing through the excitation conductor 200, W_C/W_HIs the width W of the excitation conductor 200_CWidth W of the electrode 111 ~ 115 of the longitudinal hall element 100_HThe ratio of.

As can be seen from the graph of FIG. 3, the distance h from the center of the longitudinal Hall element 100 in the substrate depth direction to the excitation conductor 200 and the width W of the electrode 111 ~ 115 of the longitudinal Hall element 100 are set to be equal to each other_HRatio h/W_HThe larger the magnetic flux density (B/I) applied to the longitudinal hall element 100 per unit current flowing in the excitation conductor 200 is, the smaller. Therefore, h/W_HSmaller is more preferable.

As is known from fig. 2, the distance h from the center of the longitudinal hall element 100 in the substrate depth direction to the excitation conductor and the width W of the electrode 111 ~ 115 of the longitudinal hall element 100 are set to be equal to each other_HRatio h/W_HThe greater the temperature rise of the excitation conductor 200.

That is, when the distance h from the center of the vertical hall element 100 in the substrate depth direction to the excitation conductor 200 becomes large, a large amount of current must be caused to flow through the excitation conductor 200 in order to apply a necessary correction magnetic field to the vertical hall element 100, and therefore, the temperature rise of the excitation conductor 200 becomes large, which affects peripheral circuits.

Therefore, even if the width W of the excitation conductor 200 is large_CWidth W of the electrode 111 ~ 115 of the longitudinal hall element 100_HRatio W of_C/W_HW is not less than 0.3_C/W_HIn the range of ≦ 1.0, the temperature rise of the excitation conductor 200 is preferably 5 ℃ or less in order to suppress the influence on the peripheral circuit.

Therefore, according to fig. 3, the distance h from the center of the longitudinal hall element 100 in the substrate depth direction to the excitation conductor 200 is equal to the electrode 1 of the longitudinal hall element 10011 ~ 115 width W_HRatio h/W_HPreferably, the width W of the excitation conductor_CWidth W of electrode 111 ~ 115 of longitudinal hall element_HRatio W of_C/W_HThe temperature rise of the excitation conductor 200 is 5 ℃ or lower and 0.4 or lower within a range of 0.3 or higher.

In the step of forming the vertical hall element 100, forming the insulating film 30 thereon, and then forming the wiring for electrically connecting a plurality of elements such as transistors constituting the peripheral circuit to each other, the excitation conductor 200 can be formed simultaneously with the wiring. Therefore, according to the present embodiment, the excitation conductor 200 can be formed without increasing the manufacturing process.

Further, the width W of the excitation conductor 200_CWidth W of the electrode 111 ~ 115 of the longitudinal hall element 100_HRatio W of_C/W_HW is not less than 0.3_C/W_H1.0, thus, for example, in the reaction of W_C/W_HIn the case of 0.5, even if the width of the excitation conductor 200 varies due to variations in the manufacturing process, W is generated_C/W_H0.5+ α or 0.5- α, and the change in magnetic flux density with respect to the change is also small as known from fig. 3. That is, even if the width of the field conductor 200 varies due to variations in the manufacturing process, variations in the magnetic field intensity generated from the field conductor 200 can be suppressed to a small level.

Here, the excitation conductor 200 is preferably formed of, for example, Al, as the resistivity is lower to reduce the amount of heat generation. Further, the thickness of the excitation conductor 200 is preferably larger in order to reduce the amount of heat generation, and is preferably 0.5 μm or more, for example.

Next, a method of compensating the characteristics of the vertical hall element 100 in the semiconductor device of the present embodiment by using the correction magnetic field will be described.

By causing a current to flow through the excitation conductor 200, a correction magnetic field Bc having a predetermined magnetic flux density indicated by a broken line is generated around the excitation conductor 200 as shown in fig. 1 (b), and thereby the correction magnetic field Bc is applied to the longitudinal hall element 100 in the left-right direction. In this case, the predetermined magnetic flux density is preferably about several mT.

In a state where the correction magnetic field Bc is applied, a drive current is supplied to an electrode that is a drive current supply electrode among the electrodes 111 ~ 115 of the vertical hall element 100. the drive current receives a lorentz force due to the correction magnetic field Bc, and thereby a voltage difference is generated between the electrodes that are hall voltage output electrodes among the electrodes 111 ~ 115 of the vertical hall element 100, and the voltage difference is obtained as a hall voltage.

The characteristics of the vertical hall element 100 are compensated by adjusting the drive current, the gain of an amplifier connected to the output of the vertical hall element 100, and the like, based on the hall voltage obtained in this manner, or the offset voltage remaining after the operation of a plurality of hall voltages obtained by changing the supply direction of the drive current by the rotating current method. In this manner, a semiconductor device having the vertical hall element 100 in which variations in characteristics are suppressed with high accuracy can be realized.

While the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the present invention.

For example, although the excitation conductor 200 is shown as a single layer in the above embodiment, a multilayer wiring may be used to increase the thickness of the entire excitation conductor 200, and the thickness of the entire excitation conductor 200 may be increased.

Although AL or the like is used as the excitation conductor 200, a conductor such as polysilicon may be used.

In addition, although the description has been made with the 1 st conductivity type being P-type and the 2 nd conductivity type being N-type, the 1 st conductivity type may be N-type and the 2 nd conductivity type may be P-type by exchanging conductivity types.

In the above-described embodiment, the vertical hall element 100 has 5 electrodes, but the vertical hall element 100 may have 2 electrodes for supplying a driving current and 1 electrode for outputting a hall voltage, which are 3 or more electrodes in total.

Description of reference numerals

10 semiconductor substrate

20 element separation diffusion layer

30 insulating film

100 longitudinal Hall element

101 semiconductor layer (magnetic sensing part)

111 ~ 115 electrode

200 excitation conductor

Bc correction magnetic field

W_CWidth of excitation conductor

W_HWidth of the electrode

And h distance.