JPS58209185A - Magnetoelectricity converting element - Google Patents

Abstract

PURPOSE:To reduce the unbalanced voltage as well as to lessen the drift of this voltage for the titled converting element by a method wherein an N type or P type magnetoelectricity conversion working layer is formed on a GaAs substrate and, in the case where an element is constructed in such a manner that a metal electrode is connected to the end part of the working layer, a high density region consisting of the impurities same as those of the working layer is provided between the working layer and the electrode. CONSTITUTION:After a negative type photoresist has been rotary-painted on a Cr- doped GaAs insulated substrate 1, an aperture is provided, and an N type magnetoelectricity conversion working layer 2 is formed by performing an Si<+> ion implantation. Then, an aperture is provided again by renewing the photoresist, an Si<+> ion is implanted in the same manner, and an N<+> type layer 9 is formed in the substrate 1 including the end part 2' of the layer 2. Subsequently, an SoP2 film is covered on the whole surface, a window is provided at the part 7 where ohmic contact with the electrode metal will be formed, and an AuGe electrode 3 is adhered on the end part 2 through the layer 9. Thus the conductivity of the layer 9 located below the electrode 3 is increased and the influence of crystal effect is reduced by having a uniform ohmic contact on the interface between the layrs 9 and 2.

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention relates to a magnetoelectric transducer, and in particular to a GaAs transducer that produces an output (Hall 4 voltage) in the direction of a curve in the direction of current flow and the direction of a magnetic field.
This relates to Hall elements.

[One point regarding the technical background of the invention and background art] FIG. 1 shows the general configuration of a Hall element. In the figure, l is an Or-doped Ga 8 crystal insulating substrate, c is a substantially cross-shaped magnetoelectric conversion layer formed by implanting an N-type impurity, such as 81+, into the insulating substrate l, and J! L, Jb
, jc, 3d are metal electrodes arranged at one end of the active layer λ, and 1,7a, , ? b is a current electrode, 3
C, J (l is the output' electrode.

Figure 1 shows the structure of the trunk part.

The electrodes 3 (electrodes 3a to Jd in FIG. 1) are formed as follows. That is, after forming the active layer as described above, OVD (Chemical Vapor De
position) 5102 is formed on the entire surface using the device W, and the portion 6102 that is to have an ohmic connection with the polarizing metal is etched away using the PEP (photo-etching) method.
Open window 7.

On top of that, a metal capable of forming an ohmic junction with the active layer 2 (N4 GaAs), such as AuGe, is deposited on the entire surface, and then a 1.1 billion layer is formed by a two-hole method, and then the temperature is raised to a temperature higher than the eutectic temperature of AuGe. Raise the temperature and obtain ohmic junction.

The Hall element uses the Hall effect, and the electrode, 7a
, ,? When a current Ic is passed between B and a magnetic field B is applied in the theoretical direction (perpendicular to the plane of the paper), a Hall voltage VH expressed by the following equation is generated in the case of constant current operation.

VH-KH・Eng.・B Here, KM is a practical coefficient called product sensitivity.

When the magnetic field B-o is present, VH theoretically becomes 0, but in reality it has a certain sharpness due to the asymmetry of the cross-shaped operating layer 2, local anomalies, and electric field concentration near the electrodes. value. This voltage V)io Y is called the unbalanced voltage. Then, there is a problem that a drift occurs in this non-PJii voltage VHO.

Electric field concentration near the electrode is caused by unevenness around the edge of the electrode window formed by etching, alloy metal (ohmic joint)
Local inhomogeneity of the ferrite is caused by crystal defects induced by alloying.

[Purpose of the invention]

An object of the present invention is to provide a magnetozeoconversion element with a small VNO and a small VHO drift.

[Summary of the invention]

The magnetoelectric conversion element of the present invention has an N layer or a P layer interposed between a lq-type or p-type magnetoelectric converter and a gold electrode.

[Embodiments of the invention]

The Hall element according to the present invention has the same overall configuration as that in FIG. 1, but as shown in FIG. The connecting portion with the metal electrode 3 is different. That is, the lower K N+ of gold h4 awakening pole 3
A layer D is formed and a metal electrode is connected to the N-type actuator J-,2 through eight layers. Dotted line Ko1 in H1 No. JiJ
indicates a portion of one layer that is first formed together with the active layer λ.

A method for forming a Hall element having such a configuration is, for example, as follows. 1. GaA3 crystal doped with Or. 2. Apply negative type photoresist to plate l.
After spin-coating to a thickness of 3 μm, the part that would become the N layer was exposed using a PEP method, and 10 Sl was applied using an ion implantation device at an acceleration voltage of 200 KeV and a dose of
x 10122 α Input. Next, the above photoresist was peeled off, and a negative type photoresist was spin-coated again to a thickness of 2.5 μm, and NN? Exposing the part where S1+ is
Enter cm. Next, the photoresist is peeled off. After that,
Annealing is performed at 00° C. for 2 minutes in an AsH4 gas atmosphere to activate the ion-implanted Sl and form an N-type active layer and an N+ layer.

After the physical, from the OV'D device tK, the thickness of JOOOA is 5.
102 film is formed on the entire surface, and the s1'o+ film in the portion 7 that forms an ohmic contact with the electrode metal is etched to form a window. In this case, is it the end of the second active layer of window 7, or the N layer? It is preferably set back to the N layer 9 side by about i0 Prn or more from the interface between the first layer and the N+ layer. Next, using Yakui Beam Gun Vapor Deposition Equipment Co., Ltd., we deposited AuGa (Ga content: 12q6) of
) was evaporated at 5000 A, and the electrode 3 was formed by the PR) method. After removing the resist, 1
．． Alloying is achieved by heating at l1tOθ°C for 1.0 minutes to form a V co-ohmic junction between the superpole 3 and the 8-layer electrode.

The joint between the N+ layer and the metal electrode 3 includes the joint between the N-type active layer and the metal electrode 3 (in the case of FIG. 2).
Similarly, crystal defects occur. However, while the 10N layer has high conductivity and acts as a conductor,
Since the interface between layer D and active layer C forms a uniform and good ohmic junction, the influence of crystal defects is small. In addition, as shown in Figure 1, by forming the N layer D thicker than the active layer (for example, for the active layer K of about 0.λμ, make NMt? about o, srμ), The influence of defects can be further reduced. As a result, WHO and its drift due to electric field concentration can be significantly reduced.

-For example, element resistance (Rd) fθθ~1ooo
Ω, in constant current operation, VHo < at Icw z-
! rmV, and voltage (! -10mA, VHO drift (0.4 <mV) has become a town's policy.

In the embodiment shown in FIG. 3, the window 7 is formed in a part of the N layer D, but in the part other than the side where the first layer 9 contacts the active layer D, the window 7 (therefore, the connection with the electrode 3 part) may protrude from the layer.

FIG. 3 shows an example.

Further, the N-type active layer 9 and the N-type active layer 9 are not limited to those formed by the ion implantation method, but may be formed by other methods such as a diffusion method. Furthermore, the semiconductor
Although a Hall element has been described in which an active layer and an N layer are formed by adding a type impurity, a Hall element may be formed in which a P5 active layer and a P# are formed by adding a P type impurity.

〔Effect of the invention〕

As described above, in the magnetoelectric conversion element of the present invention, a layer having a higher impurity concentration than the active layer is interposed between the can-shaped conversion active layer and the metal electrode, so that 1. The effects of non-uniformity of the alloy layer between the two layers, crystallization strain, etc. are small, and the non-average voltage vHe and its drift can be significantly reduced.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing the overall configuration of an example of a Hall element,
FIG. 2 is a plan view showing an overlapping portion of a conventional Hall element, FIG. 3 is a plan view showing an electrode portion of an embodiment of the Hall element of the present invention, and FIG. Line ``Prayer drawing, Fig. S+! A plan view of another example of the Hall element of the present work, with the ``4'' part removed.／...IjaAs crystal high-glow substrate, co...・N monk Buddha translation movement) -13, 3a~3d...metal d4s, 7.
...Anger? ...even more.

Claims (1)

[Claims] A magnetoelectric conversion element comprising a GaAs crystal substrate, a magnetoelectric conversion active layer formed by adding an impurity that makes the GIS-Aa crystal N-type or P-type, and a metal electrode connected to the end of the active layer. In the magnetoelectric converter+Ii, a layer formed by adding an impurity equivalent to that of the magnetoelectric converter layer at a higher concentration is interposed between the magnetoelectric converter layer and the metal electrode. ! Yuko.