JP3431326B2 - Hall element and electric quantity measuring device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention utilizes an output voltage of a Hall element that is proportional to an input current or a magnetic field, an ammeter, a magnetometer, an angular displacement meter, and an output voltage which is proportional to a product of an input current and a magnetic field. The present invention relates to an electric quantity measuring device such as a multiplier, an electric power meter, and a phase meter, which uses an electric field, and a characteristic improvement of a hall element used in the electric quantity measuring device.

[0002]

2. Description of the Related Art Hall elements utilizing the Hall effect of semiconductors are widely used in various electric quantity measuring devices. Hereinafter, such a Hall element will be described with reference to FIG. The figure (a) is a top view and the figure (b) is a longitudinal cross-sectional view of AA '. Hall element 11 has a high acceptor concentration p
^The n ⁻ layer 13 is grown on the ⁺ substrate 12, and the current input terminals I ₁ and I ₂ and the voltage output terminals V ₁ and V ₂ are provided on the ⁺ layer 13 at positions orthogonal to the current flowing direction. S is a substrate terminal connected to the substrate 12. The magnetic field is applied in the direction orthogonal to the paper surface in FIG. When used as an ammeter, the output voltage is measured with a constant magnetic field strength, and when used as a flux meter, the output voltage is measured with a constant input current. When used as a multiplier or a power meter, an output voltage is measured by adding a current proportional to the voltage of the system under test and a magnetic field proportional to the current of the system under test.

[0003]

However, in the above-described conventional Hall element, since the depletion layer 14 with almost no carriers is formed in the n ⁻ layer on the substrate 12, the resistance value of the current path changes greatly. There was a problem. Therefore, when the voltage of the system under measurement is applied to the current input terminal, a current proportional to the voltage does not flow and a measurement error occurs. The thickness L of the depletion layer in the pn junction is expressed by the following equation: pn
It is proportional to the square root of the diffusion potential difference V _{o at} the junction surface.

[0004]

[Equation 1] Here, ε is the dielectric constant, q is the electron charge, N _A and N _D are the acceptor concentration in the p-type region and the donor concentration in the n-type region, respectively. For example, as shown in FIG. 6A, the substrate terminal S is connected to -5V which is the lowest potential of the power supply used, and the current input terminals I ₁ and I ₂ are + 2V and 0, respectively.
When V is applied, the depletion layer 14 on the side of the current input terminal I ₁ becomes thicker as shown in FIG. In addition, the current input terminals I ₁ , I
_When -2V and 0V are applied to ₂ respectively, the same figure (b)
As described above, the depletion layer 14 on the side of the current input terminal I ₂ becomes thick.
Since the thickness of the depletion layer no current flows by such a current input terminal I _1, the voltage applied to the I ₂ varies, the resistance value between the current input terminal I _1, I ₂ varies.

Further, there is a problem that variations in the characteristics of the Hall element due to the shift of the mask pattern at the time of semiconductor manufacturing, offsets due to the piezo effect due to mechanical strain after manufacturing, and variations in electrical resistance occur. It was

The present invention has been made in order to solve such a conventional problem, and a Hall element in which a depletion layer is not formed and variation in characteristics is small, a measurement error caused by the formation of the depletion layer, and a Hall element. It is an object of the present invention to provide an electric quantity measuring device capable of reducing the measurement error due to the variation of the characteristics.

[0007]

[0008]

In order to solve the problem] was to achieve the above purpose
Therefore, the invention according to claim 1 is formed on a p ^{− type} semiconductor substrate.
A pair of current input electrodes provided in the n ⁻ layer exhibiting the Hall effect, a pair of voltage output electrodes provided at a position orthogonal to the current flowing between the pair of current input electrodes, and a pair of voltage outputs A pair of voltage output terminals respectively connected to the electrodes, a pair of substrate electrodes formed adjacent to the pair of current input electrodes and contacting the p ⁻ -type semiconductor substrate , and a pair of current input electrodes, respectively. The gist of the present invention is to have a pair of current input terminals connected to the pair of substrate electrodes in the vicinity.

A second aspect of the present invention is characterized in that a plurality of Hall elements according to the first aspect are formed on the same semiconductor substrate at point-symmetrical positions. Also, claim 3
The gist of the present invention is to provide the Hall element according to claim 1 or 2 .

[0010]

According to the first aspect of the present invention , since the depletion layer is not formed on the pn junction surface by taking such means, it is possible to prevent the occurrence of the error due to the variation of the resistance value.

Further, in the invention according to the second aspect, by taking such means, it is possible to reduce the error caused by the geometrical arrangement of the Hall elements at the time of manufacturing the semiconductor. Further, the invention according to claim 3 can reduce the error due to the generation of the depletion layer of the Hall element in the current measuring device and the variation of the characteristics by taking such means.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows the structure of an embodiment of a Hall element.
FIG . 2 is a plan view (FIG . 1A) and a vertical sectional view taken along the line AA ′ (FIG. 1B). In the figure, 1 is a Hall element, 2 acceptor concentration is large p low resistance ^- substrate made of type semiconductor, it is 3 n exhibits a Hall effect are formed on the substrate 2 ^- a layer. PI1 and PI2 are current input electrodes, and an n ⁺ layer having a low resistance value is formed at the connection portion.
PV1 and PV2 are voltage output electrodes provided at positions orthogonal to the current flow direction, and an n ⁺ layer having a low resistance value is formed at the connection portion. The current input electrodes PI1 and PI2 and the voltage output electrodes PV1 and PV2 are the current input terminals I1 and I1, respectively.
It is connected to I2 and the voltage output terminals V1 and V2. P
S1 and PS2 are substrate electrodes provided in the vicinity of the current input electrodes PI1 and PI2 (in the present embodiment, in parallel with the outer sides of the current input electrodes PI1 and PI2, respectively), and are p ^{− type} semiconductor substrate 2 It is connected to the. Each electrode is connected to the substrate terminals S1 and S2.

Next, taking as an example a case where the Hall element constructed as described above is used as an electric power meter,
This will be described with reference to FIG. The current of the system to be measured is converted into magnetic field strength, and the magnetic field is applied in the direction orthogonal to the paper surface of FIG. The current input terminal I ₁ and the substrate terminal S ₁ are connected to each other, and the current input terminal I ₂ and the substrate terminal S _{2 are connected to each other.}
Are connected to each other and the power supply voltage of the system under measurement is applied. For example, in the same figure (a), 0V which is the lowest potential of the power supply used is connected to the current input terminal I ₁ and the substrate terminal S ₁ ,
This is the case where + 2V is connected to the current input terminal I ₂ and the substrate terminal S ₂ , respectively, and in the figure (b), 0V which is the lowest potential of the power supply used is connected to the current input terminal I ₁ and the substrate terminal S _1. , -2V is respectively connected to the current input terminal I ₂ and the substrate terminal S ₂ . Since the current input electrode PI ₁ and the substrate electrode PS ₁ are close to each other and the current input electrode PI ₂ and the substrate electrode PS ₂ are close to each other, the potential gradient of the substrate 2 made of p ^{− type} semiconductor and the substrate 2 are The depletion layer is not formed because it almost matches the potential gradient of the formed n ⁻ layer. for that reason,
Since the resistance value between the current input terminals I ₁ and I ₂ is constant without being influenced by the applied voltage to be measured, the current flowing through the Hall element is correctly proportional to the applied voltage. Therefore, according to the configurations of the above-described embodiments, it is possible to obtain a voltage output that is correctly proportional to the power value regardless of the value of the measured voltage.

FIG. 3 is a plan view (FIG. 3 (a)) and a vertical sectional view taken along line AA '(FIG. 3 (b)) showing the structure of an embodiment of the Hall element of the present invention. In the figure,
1 Hall element, 2 acceptor concentration is large p low resistance ^- substrate made of type semiconductor, it is 3 n exhibits a Hall effect are formed on the substrate 2 ^- a layer. Current input terminal IS
1 and IS2 are a pair of current input terminals to which the current input electrodes PI1 and PI2 and the corresponding substrate electrodes PS1 and PS2 have been connected in advance, and the operation thereof is the same as that described above with reference to FIG. Therefore, in the structure of such an embodiment, it is not necessary to connect the current input terminal and the substrate terminal externally.

FIG. 4 is an embodiment of the invention described in claim 2, and the four Hall elements 1-1, 1-2, 1-3 and 1 described in claim 2 are formed on the same semiconductor substrate 4. It is a top view which shows the structure which formed -4 in the position of point symmetry. Set the current input electrodes of Hall element 1-i (i = 1, 2, 3, 4) to PI1
i, PI2i, voltage output electrodes PV1i, PV2i, and substrate electrodes PS1i, PS2i, the voltage output terminal V1 has four voltage output electrodes PV1i (i = 1, 2, 3,
4) are all connected in parallel, and similarly, the voltage output terminal V
2 has four voltage output electrodes PV2i (i = 1, 2, 3,
4) are all connected in parallel. Further, the current input terminal IS1 has four current input electrodes PI1i (i = 1, 2,
3, 4) and four substrate electrodes PS1i (i = 1, 1
2, 3, 4) are all connected in parallel, and similarly, the four current input electrodes PI2i (i = 1, 1) are connected to the current input terminal IS2.
2, 3, 4) and four substrate electrodes PS2i (i =
1, 2, 3, 4) are all connected in parallel. Therefore, in the structure of such an embodiment, the offset is reduced because the variations in the characteristics of the Hall element due to the shift of the mask pattern during semiconductor manufacturing, and the electromotive force and electric resistance due to mechanical strain after manufacturing are offset. Can be made. Although the structure of the electric quantity measuring device is not particularly shown, it is clear that the improvement of the characteristics of the Hall element according to the present invention contributes to the improvement of the accuracy of the electric quantity measuring device.

[0016]

As described above, according to the first aspect of the present invention, since the depletion layer is not formed on the pn junction surface, it is possible to prevent the occurrence of an error due to the variation of the resistance value.

According to the second aspect of the present invention , it is possible to construct a Hall element having a small offset by canceling out variations in characteristics of the Hall element and electromotive force and electric resistance due to mechanical strain. In addition, according to claim 3,
According to bright, it is possible to construct a highly accurate electric quantity measuring device.

[Brief description of drawings]

1A and 1B are a plan view and a vertical sectional view showing the structure of an embodiment of a Hall element.

FIG. 2 is an operation explanatory diagram of a Hall element.

3 is a plan view and a longitudinal sectional view showing the structure of an embodiment of the Hall element of the invention of claim 1, wherein.

FIG. 4 is a plan view showing the structure of an embodiment of the Hall element of the present invention according to claim 2 ;

5A and 5B are a plan view and a vertical sectional view showing a structure of a conventional Hall element.

FIG. 6 is an operation explanatory diagram of a conventional Hall element.

[Explanation of symbols]

1 Hall element 2 Substrate of Hall element made of p- type semiconductor 3 n- layer 4 formed on the substrate 2 and exhibiting the Hall effect 4 Hall elements I1 and I2 current input terminals in which four Hall elements are formed in point symmetrical positions V1, V2 voltage output terminals S1, S2 substrate terminals PI1, PI2 current input electrodes PV1, PV2 voltage output electrodes PS1, PS2 substrate electrodes

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) H01L 43/06 G01R 33/07 H01L 21/76

Claims (3)

(57) [Claims] 1. A p ^- holes formed in the shape semiconductor substrate
A pair of current input electrodes provided in the n ⁻ layer that exhibits the effect, a pair of voltage output electrodes provided at a position orthogonal to the current flowing between the pair of current input electrodes, and a pair of voltage output electrodes respectively. a pair of voltage output terminals connected, the formed adjacent to the pair of current input electrode
a pair of substrate electrodes in contact with the p ^{− type} semiconductor substrate; and a pair of current input terminals to which the pair of current input electrodes and the pair of substrate electrodes in the vicinity thereof are connected. Hall element. 2. A Hall element comprising a plurality of the Hall elements according to claim 1 formed on the same semiconductor substrate at point-symmetrical positions. 3. An electrical quantity measuring device comprising the hall element according to claim 1 or 2 .