BG66552B1 - Semiconductor element for hall-effect transducer - Google Patents

Abstract

The semiconductor element for Hall-effect transducer has a semiconductor pad with n-type conductivity, over one of it sides is formed central ohm contact, at some distances and symmetrically from it are formed another two end ohm contacts. The two zones which are on the end contacts external sides (3 and 4) have the acute-angled isosceles triangle forms with equal surfaces and on their acute tops there is one ohm contact (5 and 6). These zones are symmetrical in relation to the central contact (2). The two end contacts are connected between each other and through a current source they are connected with the central contact. The magnetic field is applied perpendicularly to the plane of the pad. The contacts (5 and 6) situated on the acute angles of the triangle zones are the sensors Hall output (9).

Description

Field of technology

The invention relates to a semiconductor Hall element applicable in the field of micro- and nano-electronics, sensors, contactless automation, instrumentation, energy, electrical engineering, military affairs, medicine, security systems, control and measurement technology, low-field and multidimensional vector magnetometry and others.

BACKGROUND OF THE INVENTION

A semiconductor Hall element is known, comprising a semiconductor substrate with p-type conductivity, on one of the sides of which a central ohmic contact is formed, at distances and symmetrically on it are arranged one more inner ohmic contact and one outer ohmic contact. The two external contacts are connected and are connected to the central one through a current source. The magnetic field is applied perpendicular to the plane of the substrate and the two internal contacts are the running differential output of the element [1, 2].

A semiconductor Hall element is also known, comprising a semiconductor substrate with p-type conductivity, on one of the sides of which a central ohmic contact is formed, at distances and symmetrically on it are arranged one more internal ohmic contact and one external ohmic contact. . The two internal contacts are connected and are connected to the central one through a current source. The magnetic field is applied perpendicular to the plane of the substrate and the two external contacts are the running differential output of the element [3,4].

A semiconductor Hall element is also known, comprising a semiconductor substrate with p-type conductivity, on one of the sides of which four ohmic contacts are formed in series and at distances - first, second, third and fourth. The first and third contacts are connected through a current source, the magnetic field is applied perpendicular to the plane of the substrate, and the second and fourth contacts are

The running differential output of the element [5].

The disadvantage of these Hall semiconductor elements is the exhausted capacity of possibilities for increasing their magnetic sensitivity by: optimizing the geometric dimensions of the respective instrument structures; minimizing the Hall-shortening effects of the ohmic contact arrangement; appropriate for the purpose technological methods and processes; use of semiconductor materials with high mobility of current carriers, ie with low electron concentration; application of magnetic field concentrators made of soft magnetic alloys and cryogenic temperature media.

Technical essence of the invention

The object of the invention is to provide a Hall semiconductor element with increased magnetic sensitivity by controlling the surface density of the additional current carriers generated in a magnetic field on the Running surfaces, determining the value of the Running voltage.

This problem is solved with a semiconductor Hall element, containing a semiconductor substrate with p-type conductivity, on one of the sides of which a central ohmic contact is formed, and at distances and symmetrically on it - another external ohmic contact. The two zones located between the central and external contacts are in the form of acute-angled isosceles triangles and have the same area, on the sharp tips of which there is one ohmic contact. The triangular zones are symmetrical to the central contact. The two external contacts are connected and are connected to the central one through a current source. The magnetic field is applied perpendicular to the plane of the substrate as the contacts on the sharp vertices of the triangular zones are the running differential output of the element.

This problem is also solved with a semiconductor Hall element, containing a semiconductor substrate with p-type conductivity, on one of the sides of which a central ohmic contact is formed, and at distances and symmetrically on it another end ohmic contact. The two zones located on the outside of the end contacts are acute-shaped

66552 Bl isosceles triangles and have the same area, on the sharp vertices of which there is one ohmic contact. The triangular zones are symmetrical to the central contact. The two external contacts are connected and are connected to the central one through a current source. The magnetic field is applied perpendicular to the plane of the substrate and the contacts on the sharp vertices of the triangular zones are the running differential output j θ of the element.

This problem is also solved with a semiconductor Hall element, containing a semiconductor substrate with p-type conductivity, on one of the sides of which are formed at a distance 15 two supply ohmic contacts. The zones located respectively between these contacts and on the outside of one of them are in the form of acute-angled isosceles triangles, the sharp vertices of which have one ohmic contact. The two triangular zones have the same area and are symmetrical to the respective power contact located between them. The supply contacts are connected through a current source, the magnetic field is applied perpendicular to the plane of the substrate and the contacts on the sharp vertices of the triangular zones are the running differential output of the element.

gt and 30

An advantage of the invention is the increased magnetic sensitivity of the Hall semiconductor element as a result of the reduced area of the areas on which the additional electric loads are generated in a magnetic field, 35 leading to an increase in the running voltage, i. of magnetic sensitivity.

Explanation of the attached figures

The invention is illustrated in more detail by three exemplary embodiments thereof, given in the appended Figures 1, 2 and 3.

Examples of the invention

The semiconductor Hall element shown in Figure 1 comprises a semiconductor substrate 1 with p-type conductivity, on one of the 45 sides of which a central ohmic contact 2 is formed, and at a distance and symmetrically on it - another external ohmic contact 3 and 4. The two zones located between the central 2 and the outer contacts 3 and 4 are in the form of acute-angled isosceles triangles and have the same area, the sharp vertices of which have one ohmic contact 5 and 6. The triangular zones are symmetrical with respect to the central contact 2. The two external contacts 3 and 4 are connected and through a current source 7 are connected to the central 2. A magnetic field 8 is applied perpendicular to the plane of the substrate 1, contacts 5 and 6 on the sharp vertices of the triangular zones are the running differential output 9 of the element.

The semiconductor Hall element shown in Figure 2 comprises a semiconductor substrate 1 with n-type conductivity, on one of the sides of which the central ohmic contact 2 is formed, and at distances and symmetrically on it - another end ohmic contact 3 and 4. The two zones located on the outside of the end contacts 3 and 4 are in the form of acute-angled isosceles triangles and have the same area, the acute vertices of which have one ohmic contact 5 and 6. The triangular zones are symmetrical with respect to the central contact 2. The two end contacts 3 and 4 are connected and through the current source 7 are connected to the central 2. The magnetic field 8 is applied perpendicular to the plane of the pad 1, the contacts 5 and 6 on the sharp vertices of the triangular zones are the running differential output 9 of the element.

The Hall semiconductor element shown in Figure 3 comprises a semiconductor substrate 1 with n-type conductivity, on one of the sides of which are formed at a distance the two supply ohmic contacts 2 and 3. The zones located between these contacts 2 and 3, respectively, and on the the outer side of one of them - 3 are in the form of acute-angled isosceles triangles, on the acute vertices of which there is an ohmic contact 4 and 5. The two triangular zones have the same area and are symmetrical to the respective power contact 3 located between them. Contacts 2 and 3 are connected through a current source 6, the magnetic field 7 is applied perpendicular to the plane of the substrate 1, and contacts 4 and 5 on the sharp vertices of the triangular zones are the running differential output 8 of the element.

The operation of the Hall semiconductor element according to the invention is as follows.

When connecting the central ohmic contact 2 and the respective end contacts 3 and 4 is the current source 7 at the sensors of figure 1 and figure 2, both contacts 2 and 3 with the current source

66552 Bl for the sensor of Figure 3, currents 1 ₂₃ , 1 ₂₄ and 1 ₂₃ (Figure 3) respectively flow in the semiconductor substrate 1, the trajectories of which are curvilinear. Since the supply contacts 2, 3 and 4 are $ with low resistance and represent equipotential planes, the currents 1 ₂₃ , 1 _{2 4} and 1 _{2 3} are initially directed vertically inwards in the volume of the substrate 1. Then the trajectories become parallel to the upper side of the substrate. the pad 1. 10

When an external magnetic field is applied

In 8 (for the sensors in Figure 1 and Figure 2), and in 7 (for the sensor in Figure 3), the Lorentz force F. = qV occurs. x C. It deviates laterally “ ^d 1 <

current trajectories, where they "shrink" or "expand", where V _dr is the drift velocity of the electrons, aq is the elementary load.

As a result, additional electrical loads are generated on the side with the ohmic contacts 2, 3, 4, 5 and 6 of the semiconductor substrate ₂ θ 1 - when the trajectory “shrinks” the density of electrons increases, and when “stretched” the positive donor ions dominate. crystal lattice due to reduced concentration of electrons. With fixed directions of the supply current and the magnetic field B 8 for the sensors symmetrical to the central contact 2 of figure 1 and figure 2, to the left of contact 2 the trajectory, for example, "shrinks" and to the right - it "expands" (currents 1). _{2 3} and -1 _{2 4} are opposite). Therefore, in the area to the left of contact 2, the concentration of moving electrons will increase, and to the right 3 5 of contact 2 - will decrease. For the sensor of Figure 3, the trajectory of the supply current 1 _{2 3} "shrinks" in the area between the supply contacts 2 and 3, or "expands", depending on the directions of the current 1 ₂₃ and the magnetic field B 7. The concentration of the moving current carriers between contacts 2 and 3 increase, and outside them, for example on the right side of contact 3, the concentration of electrons decreases. Within the known solution for the sensor element, the travel contacts register the plane density of the additional electrons, 45 changed by the action of the Lorentz force F _r

In the Hall effect sensor, however, no.

A solution is used to increase the magnetic sensitivity by "non-magnetic" control of the surface density of the additional loads generated by the force F ,. It is well known from electrical engineering that the potential V of an electrically charged surface is a function of its area S. With a fixed amount of electrical loads Q = const, by analogy with the capacitor, the potential V of the surface area is inversely proportional to the area S on which these loads are located, V ~ 1 / S. With regard to Hall sensors, it follows that the smaller the area of the surface area on which the additional electrical loads are concentrated by the Lorentz deflection force, the higher will be the Hall potential and, accordingly, the Hall voltage V _H. Therefore, by non-magnetic control of the surface density of the additional loads through the area S of the respective zones, where they are located, the possibility of increasing the Hall voltage V _H , V _H ~ 1 / S is discovered. In the proposed new solutions of the three Hall semiconductor elements (Figure 1, Figure 2 and Figure 3) for the first time as a method to further increase the magnetic sensitivity is used to increase the surface density of loads by reducing the area S on which they are located. The chosen shape of acute-angled isosceles triangles of the zones to which the Lorentz force F _L deflects the moving electrons is the most suitable, because in the direction of their acute tip the effective area S _{eff is} strongly reduced. As a result, it is there that the electron density increases significantly, and as a consequence the Hall voltage V _{H increases} . For this reason, the travel contacts 5 and 6 (for the sensors in Figure 1 and Figure 2) and the Hall contacts 4 and 5 (for the sensor in Figure 3) are located on these sharp tips.

The unexpected positive effect of the proposed technical solution is a consequence of the original Hall construction - the triangular shape of the zones with running contacts, influencing the load density and increasing the voltage V _H (B) of the respective outputs 8 and 9.

Experiments with prototypes of discrete Hall Hall silicon elements according to Figure 1, Figure 2 and Figure 3 show that under the same conditions - the same temperature, semiconductor material, geometric dimensions, supply current and value of magnetic induction, the new solutions generate about 18%

66552 Bl higher magnetic sensitivity than known sensors. The new version of the Hall converter can also be implemented with integrated silicon technology, such as BiCMOS, CMOS or micromachining. $

Claims (3)

Patent claims A Hall semiconductor element comprising a semiconductor substrate with p-type conductivity, on one of the sides of which a central ohmic contact is formed, and at distances and symmetrically on it another external ohmic contact, the two external contacts are connected and through a current source are connected to the central, and the magnetic field is applied perpendicular to the plane of the substrate, characterized in that the two zones located between the central (2) and external (3 and 4) contacts are in the form of acute isosceles triangles of equal area, on the sharp vertices of which one ohmic contact (5 and 6) is located, and the triangular zones are symmetrical with respect to the central contact (2), the contacts (5 and 6) on the sharp vertices of the triangular zones being the Hall differential output (9) of the element. Hall semiconductor element according to claim 1, characterized in that the two zones in the form of acute-angled isosceles triangles and with the same area, at the sharp vertices of which there is one ohmic contact (5 and 6) are located on the outer sides of the end contacts (3 and 4), which are symmetrical to the central contact (2). Hall semiconductor element according to Claim 1, characterized in that the two zones in the form of acute-angled isosceles triangles, which have the same area and whose sharp vertices have one ohmic contact (4 and 5), are respectively located between the supply contacts (2 and 3) and on the outside of one of them (3), as they are symmetrical with respect to the power supply contact (3) located between them.