JPS5842282A - Hall element - Google Patents

Abstract

PURPOSE:To increase the magnetic sensitivity for the titled element by a method wherein the interval between two current input electrodes, which were provided facing each other on both end parts of a substrate, is made narrower in the center part and wider at both side face sections. CONSTITUTION:Current input electrodes 1 and 2 are provided at both end parts of a semiconductor substrate 10, and Hall output electrodes 31 and 32 are provided at both side face sections of the substrate 10. The interval between the current input electrodes 1 and 2 is narrowed in the center part and widened at both side face sections. As a result, the short-circuit effect between the current input electrodes 1 and 2 and the Hall output electrodes 31 and 32 can be reduced, and a high magnetic sensitivity can also be obtained. The surface inversion layer located between the source and the drain of MOST can be used as a semiconductor substrate part displaying Hall effect, and the source and drain diffusion layer can be used as a current input electrode. A diffusion layer of the same conductive type as that of the source and drain is provided as a Hall output electrode.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a Hall element having a total improvement in magnetic sensitivity and having current input electrodes on both sides.

A Hall element is often used as one of the elements that generates magnetic Ks, but the structure of the conventional Hall element is as follows.

A piece of material 1 showing a rectangular Hall effect as shown in Figure 1.
Current input electrodes 1.
is attached, and Hall output electrodes 51 and 52 are provided on both sides of this semiconductor piece 100. When a current tltIt- is caused to flow from this Hall element Kmfi input electrode 1.2 and a magnetic field Bt is applied perpendicularly to the semiconductor surface, the semiconductor piece 1
A lateral Lorentz force acts on the carriers flowing through the carrier, causing the carriers to be biased to one side, creating an internal Hall electric field and running Hall output electrodes 51. A Hall voltage vM is observed in relation to S'2. 1st! ! In the conventional electron beam shown by IK, when the voltage applied to the -current input electrode 1.2 is constant and a constant magnetic field perpendicular to the semiconductor chip 10 is applied, the Hall voltage Vi (i.e., the magnetic sensitivity of the Hall element [
FIG. 1 shows the ratio v/L (ratio of the radius W between the Hall output electrodes 51 and 52 to the length T between the current input electrodes 1 and 2). That is, while the value of W/TJ is small, the magnetic sensitivity sm increases in proportion to W/LK, but as the value of VL increases, the magnetic sensitivity 81 saturates at 811mlLX. This plane magnetic holder f81
Since 1maX is determined by the degree μ of the bull conductor,
This saturation magnetic sensation 1[BHxnhx or more i! ! Attempts to obtain a sensitive Hall element have met with little success. For example, it has been theoretically and experimentally proven that a trapezoidal Hall element as shown in FIG. 2 is completely equivalent to a rectangular Hall element having the ratio W/L shown in FIG. In addition, it has been proven that a Hall element with a fan-shaped or diamond-shaped element shape is equivalent to a 111M rectangular Hall element, so by changing the element shape, the height of the magnetic part jft (which is difficult to Ta.

The present invention aims to provide a Hall element with a novel shape that can obtain a magnetic sensitivity greater than the summed magnetic sensitivity simax obtained with a conventional rectangular Hall element shape.

In the conventional rectangular Hall element, the magnetic sensitivity is 8M w
The reason for saturation with respect to the value of /b is thought to be that the generated Hall voltage is short-circuited to the current input electrodes 1 and 2, causing a decrease in the Hall voltage that should theoretically be reduced by 6. . Therefore, in order to obtain high magnetic sensitivity, it is only necessary to reduce the short circuit sound effect between the current input electrodes 1 and 2 and the output electrodes 51 and 52. Based on this idea, a Hall element having a novel current input electrode structure is shown in FIG. 4. In FIG. According to this shape of the present invention, the side parts near the Hall output electrodes 51 and 52 are far away from the current input electrodes 1 and 2, so the Hall voltage appearing here is equal to the current input It is clear that it is affected by the short circuit caused by electrode 1.2. On the other hand, in this side part, the electric field 71 F is weaker than the electric field in the center part because the distance between the current terminals 1°2 is wider than in the center part, and as a result, the electric field 71 F is weaker locally in the side part. The downside is that the Hall electromotive force is weakened.

However, according to the calculation results and experimental results of a Hall element with this shape, the saturation magnetic sensitivity obtained with a conventional rectangular Hall element is 51g1rxnc.
Hall element t with 20% to 30% more magnetic sensitivity than 8mmmax
-Easy to obtain.

FIGS. 5 and 6 show embodiments of a Hall element having an input electrode shape according to the present invention.

Above we have discussed a Hall element that utilizes the Hall effect of a piece of conductor with a uniform film thickness, but the above one is MOB)
This can also be applied to a Honil element in which the channel of the transistor is the main converter. In the rectangular Mol-type Hall element shown in No. 7 @, increase the w/Lv value of the rectangular channel 20 determined by the distance between the drain diffusion layer 6 and the source diffusion layer 7 and the width W of the gate 21! (
L, W#.

Of course, when the magnetic sensitivity of the Hall voltage appearing in the Hall output electrodes 56 and 579C formed by the same diffusion layers as the drain diffusion layer 6 and the source diffusion layer 7 is operating in its non-saturation region, , even when operating in the saturation region, it is saturated with kSHmaX as shown in FIG. 5, and has a saturation magnetic sensitivity BHWaX. It has been proven both experimentally and theoretically that it is impossible to achieve magnetic sensitivity exceeding this saturation magnetic sensitivity with a Hall element having a channel shape such as a trapezoid, sector, or rhombus. However, as shown in Figure 8, MOB
) The M of the present invention has a shape in which the drain-source distance of the transistor is good near the Hall output electrodes 56 and 57.
OB)) In a pole element using a resistor, its magnetic sensitivity can be easily made higher than the saturation magnetic sensitivity of the rectangular MOBIJi Hall element of the seventh factor.

As mentioned above, according to the present invention, it is possible to easily produce a home device with high sensitivity, which could not be achieved with conventional Hall elements, which is believed to contribute to the yield of home devices and, ultimately, to lower prices. It will be done.

[Brief explanation of the drawing]

Figure 1 shows the structure of a conventional rectangular Hall element, Figure 2 shows the structure (2) of a conventional trapezoidal Hall element, and Figure 5 shows the magnetic sensitivity of the Hall element in the first area. Figures 1, 15 and 6 are diagrams showing the shape dependence, respectively. FIG. 8 shows an embodiment of a MO8fil element according to the present invention. 1.2--1st current input electrode, +10-- single conductor. 51, s2・*-le output IH1, 6---yvy expansion 7---source diffusion layer, diffusion layer, 36.
57... Diffusion layer as a hole output electrode. That's all Figure 1 Figure 2 389- Figure 3 Base Heel Calmness 5M is east, scale) Figure 4 Knee 5rIA''- 6r! A

Claims (2)

[Claims] (1) In a Hall element in which input electrodes are provided at both ends of a piece of material exhibiting the Hall effect, and Hall output poles are provided on both sides of the material piece, the barriers of the current input electrodes facing each other are A Hall element characterized by being narrow at the center and wide at both sides. (2) The material piece exhibiting the Hall effect is an inversion layer near the semiconductor surface between the source and drain diffusion layers of the M08 transistor, the current input electrode is the source and drain diffusion layer, and the Hall output electrode is the source and drain diffusion layer. - The Hall element according to claim 1, wherein the diffusion layer is of the same conductivity type as the drain diffusion layer.