WO2015189023A1

WO2015189023A1 - Magnetic field sensor arrangement, corresponding manufacturing method and operating method

Info

Publication number: WO2015189023A1
Application number: PCT/EP2015/061530
Authority: WO
Inventors: Christian Patak; Achim BREITLING
Original assignee: Robert Bosch Gmbh
Priority date: 2014-06-13
Filing date: 2015-05-26
Publication date: 2015-12-17
Also published as: DE102014211311A1; TW201602609A

Abstract

The present invention relates to a magnetic field sensor arrangement, to a corresponding manufacturing method and to an operating method. The magnetic field sensor arrangement comprises an ASIC substrate (AC; AC) having a front face (VS) and a rear face (RS) and a hall sensor device (H; Η'; H") which has a hall sensor region (HS; HS'; HS") that consists of a III-V semiconductor material, said region being embedded in an insulation layer arrangement (I0, I1, I2, I3; I0, I1, I2, I3, I4, I5) applied to the front face (VS). The hall sensor region (HS; HS'; HS") is electrically connected to a hall sensor evaluation circuit device (101) formed in the ASIC substrate (AC; AC'), via a conductor unit (L2) guided through the insulation layer arrangement (I0, I1, I2, I3; I0, I1, I2, I3, I4, I5).

Description

description

title

Magnetic field sensor arrangement, corresponding manufacturing method and

Operating Method The present invention relates to a magnetic field sensor arrangement, a corresponding production method and an operating method.

PRIOR ART DE 10 2008 042 800 A1 discloses a device for measuring the direction and / or strength of a magnetic field. The device is arranged on a substrate. On the surface of the substrate, a Hall sensor is arranged, which is provided to detect a magnetic field component in the z-direction, which acts substantially perpendicular to the surface of the substrate. Furthermore, two fluxgate sensors are provided to detect a magnetic field component in the X-Y plane of the

Demonstrate substrate. Together with the Hall sensor thus three components in all three spatial directions can be determined.

The Hall sensor is provided in this device on or in a silicon substrate, whereas the two fluxgate sensors are manufactured separately by micromechanical components and subsequently fixed on the surface of the silicon substrate.

DE 10 2012 209 232 A1 describes a magnetic field sensor having a first magnetic sensor core for measuring a magnetic field in a first measuring direction and a second magnetic sensor core for measuring a magnetic field in a second measuring direction, wherein the first and second magnetic sensor cores have a common magnetic anisotropy. The sensor cores are components of flip-core fluxgate sensors, which are suitable for detecting magnetic fields in the wafer plane. No. 6,536,123 B1 describes a magnetic field sensor with two fluxgate sensors and a Hall sensor, wherein a hybrid IC is used to evaluate the sensor signals. It is well known that Hall-effect sensors can be fabricated on a substrate with Ill-V semiconductor materials. US Pat. No. 6,803,638 discloses an InSb Hall sensor which is deposited on a GaAs substrate by molecular beam epitaxy.

Disclosure of the invention

The present invention provides a magnetic field sensor arrangement according to claim 1, a corresponding manufacturing method according to claim 1 1 and an operating method according to claim 13. Preferred developments are the subject of the respective subclaims. Advantages of the invention

The idea underlying the present invention is to provide at least one Hall sensor region formed of an III-V semiconductor material above an ASIC substrate.

The magnetic field sensor arrangement according to the invention according to claim 1 and the corresponding manufacturing method according to claim 1 1 allow a direct

Deposition of the Hall sensor region formed from the III-V semiconductor material, in particular an InSb (indium antimonide) semiconductor region over an ASIC wafer substrate. Thus, the Ill-V semiconductor material can be directly on a

Integrating evaluation wafer of the magnetic field sensor arrangement. This allows a smaller size, lower costs, lower power consumption and a higher data rate.

In contrast to a Hall sensor region integrated in a silicon wafer, the Hall sensor region according to the present invention provides a substantially improved performance. Due to the possible integration of further sensor areas, such as magnetic core areas and magnetic coil devices for fluxgate sensor devices, a compact multidimensional, in particular three-dimensional, magnetic field sensor arrangement with a small housing size can be created.

According to a preferred embodiment, the Hall sensor region is formed from InSb. This material can be particularly controlled by applying sputtering.

According to a further preferred embodiment, the Hall sensor region has a layer sequence with material layers of different crystal grain size. This promotes adhesion and cohesion of the Hall sensor area on the substrate.

According to a further preferred embodiment, alternating first layers with a first crystal grain size and second layers with a second

Crystal grain size is formed, wherein the second crystal grain size is substantially smaller than the first crystal grain size. This leads to an advantageous toothing of the layers

According to a further preferred embodiment, at least one

Fluxgate sensor device comprising a magnetic core region formed from a ferromagnetic material and a magnetic coil device, embedded in the insulation layer arrangement applied to the front side, wherein the

Magnetic core region and the solenoid device via a through the

Insulation layer arrangement guided second conductor path means is electrically connected to a fluxgate sensor evaluation circuit means formed in the ASIC substrate. Thus, a combination sensor arrangement can be formed, for example an SD sensor.

Magnetic sensor.

According to a further preferred embodiment, the Hall sensor device and the Fluxgatesensoreinrichtung in different levels of

Insulating layer arrangement embedded. This enables good insulation and easy processability.

According to a further preferred embodiment, the Hall sensor region is arranged above or below adjacent to an end of the magnetic core region. Thus, a dual function of the Hall sensor device can be realized, which allows a gain in space. According to a further preferred embodiment, a magnetic field flux concentrator region formed from a ferromagnetic material is embedded in the insulation layer arrangement above or below the Hall sensor region. This increases the measurement performance.

According to a further preferred embodiment, the magnetic flux concentrator region is formed as a hollow cylinder whose cylinder axis is substantially perpendicular to the Hall sensor region. This allows a favorable field distribution.

According to a further preferred embodiment, the magnetic core region and / or the Flußkonzentratorbereich of Ni / Fe / Al is formed. This material can be controlled using thin-film technology.

Brief description of the drawings

The present invention will be explained in more detail with reference to the exemplary embodiments indicated in the schematic figures of the drawings.

Show it

1 is a schematic plan view of a magnetic field sensor device according to a first embodiment of the present invention;

FIG. 2 is a schematic cross-sectional view of the magnetic field sensor device according to the embodiment of the present invention taken along the line A-A 'in FIG. 1; FIG. Fig. 3 is a schematic enlarged cross-sectional view of

Hall sensor portion of the magnetic field sensor device according to the first embodiment of the present invention;

4 is a schematic plan view of a magnetic field sensor arrangement according to FIG

second embodiment of the present invention; Fig. 5a) is a schematic enlarged cross-sectional view of a

Hall sensor area of a magnetic field sensor arrangement according to a third embodiment of the present invention; and a schematic plan view of the Hall sensor area of

Magnetic field sensor arrangement according to the third embodiment of the present invention.

Embodiments of the invention

In the figures, like reference numerals designate the same or functionally identical

Elements.

1 is a schematic plan view of a magnetic field sensor device according to a first embodiment of the present invention, and FIG. 2 is a schematic cross-sectional view of the magnetic field sensor device according to the embodiment of the present invention taken along the line A-A 'in FIG. 1.

In Figs. 1 and 2, reference numeral AC denotes an ASIC substrate, in particular

Wafer substrate, with a front VS and a back RS. A

Hall sensor device H, which has a Hall sensor region HS formed from a 111 V semiconductor material, here of InSb (indium antimonide), is in an applied on the front side VS insulation layer arrangement with a plurality of insulating layers I0, 11, 12, 13, for example of oxide embedded.

As can be seen from Fig. 2, the Hall sensor area HS via a through the

Insulating layers I0, 11, 12 of the insulating layer arrangement I0, 11, 12, 13 guided first conductor track device L2 electrically connected to a Hall sensor in the ASIC substrate evaluation circuit 101 formed.

For this purpose, conductor track layers (not shown) are deposited and patterned within the insulation layer arrangement 10, 11, 12, 13 and corresponding vias are formed for the plated-through holes. The conductor track device L2 is shown only schematically in FIGS. 1 and 2 for reasons of clarity and in fact has a plurality of conductor tracks which are required for the functions of the Hall sensor device H. Furthermore, two fluxgate sensor devices F1, F2 are embedded in the insulation layer arrangement 10, 11, 12, 13 applied to the front side VS.

In the present example, a first fluxgate sensor device F1 is provided which has a first magnetic core region FC1 and a first magnetic coil device SE1. A second fluxgate sensor device F2, which is arranged orthogonal to the first fluxgate sensor device F1, has a second magnetic core region FC2 and a second magnetic coil device SE2. The magnet coil devices SE1, SE2 usually have an excitation coil and a pick-up coil.

As can be seen from Fig. 2, the magnetic core portions FC1, FC2 and the

Magnet coil devices SE1, SE2 via a through the insulating layers I0, 11 of the insulating layer arrangement I0, 11, 12, 13 guided second conductor track device L1 electrically connected to a Fluxgatesensor- evaluation circuit 100 formed in the ASIC substrate AC.

The conductor track devices L1, L2 are made of aluminum, for example.

The magnetic field sensor arrangement shown in FIGS. 1 and 2 is thus a

Three-dimensional magnetic field sensor, wherein the fluxgate sensor devices F1, F2 measure the magnetic field components in the x- and y-direction, whereas the

Hall sensor device H measures the magnetic field component in the z-direction.

For the production of the magnetic field sensor arrangement shown in FIGS. 1 and 2, the ASIC substrate AC forms the basis. On the ASIC substrate AC is a first

Insulation layer applied I0, which, for example, of silicon oxide or

Silicon nitride exists. In a subsequent process step, the ferromagnetic material of the magnetic core regions FC1, FC2 is applied to the first insulating layer 10 by thin-film technology and patterned, for example Ni / Fe / Al

(Nickel / iron / aluminum). Subsequently, a second insulating layer 11 is applied, in which the structured magnetic core areas FC1, FC2 are embedded. Subsequently, the III-V semiconductor material for the Hall sensor region HS is formed by a sputtering method multilayer applied and structured. This Hall sensor area HS is then embedded in a third insulation layer 12 and finally a fourth insulation layer 13 is deposited, which insulates the structure towards the top. Not shown and described are the known process steps of

Forming conductor tracks and other isolation levels and vias to form the conductor tracks L1, L2 and the steps for forming the first and second coil devices SE1, SE2. The Hall sensor device H and the Fluxgatesensoreinrichtungen F1, F2 are thus embedded in different levels of the insulation layer arrangements I0, 11, 12, 13, which, however, if necessary. Not required.

Fig. 3 shows a schematic enlarged cross-sectional view of

Hall sensor portion of the magnetic field sensor device according to the first embodiment of the present invention.

As can be seen from FIG. 3, in this embodiment, the Hall sensor area HS is formed by a layer sequence S1, SS1, S2, SS2, S3, etc. with material layers

different grain size formed by a sputtering process, wherein the

different grain size is achieved in particular by temperature variations during sputtering, so as to obtain the smoothest possible morphology.

In the present example, a typical range of variation for the sputtering temperature is 250 to 450 ° C. Here, in the present example, first layers S1, S2, S3 having a first crystal grain size and second layers SS1, SS2 having a second crystal grain size are alternately formed on a start layer ST of InSb, the second crystal grain size being substantially smaller than the first crystal grain size. typical

Crystal grain sizes for the first and second layers are 5-50nm and 500-1000nm.

Such smooth morphology of the Hall element brings better processability for the following process levels, as the alignment marks remain visible, and a lower electrical offset. 4 shows a schematic plan view of a magnetic field sensor arrangement according to a second embodiment of the present invention. In the second embodiment according to FIG. 4, the ASIC chip is designated by reference AC. Embedded on its front VS is a single

Fluxgate sensor device FO with a magnetic core region FCO formed from a ferromagnetic material and a magnet coil device SEO with a single magnet coil which merely serves for excitation. A Hall sensor area HS 'is arranged above or below a first end E1 of the magnetic core area FCO, the second end being designated by reference E2. The embedding of the Hall sensor area HS 'and the Fluxgatesensoreinnchtung FO with the magnetic core area FCO and the solenoid coil SEO in the SEO

Insulation layers 10, 11, 12, 13 are analogous to the first described above

Embodiment. In this second embodiment, a saving of the pick-up coil is the

Fluxgatesensoreinnchtung FO possible because you can use the Hall sensor device H 'for detecting a flux change after excitation of Fluxgatesensoreinnchtung FO. In particular, the moment of the remagnetization of the magnetic core region FCO is detected on the basis of the change in the magnetic field in the z direction detected by the Hall sensor device H '.

Of course, it is also possible to place a further Hall sensor region at the second end E2 of the magnetic core region FCO either above or below it in order to increase the measurement sensitivity or measurement accuracy.

This embodiment has the advantage that the component can be made smaller.

Fig. 5a) shows a schematic enlarged cross-sectional view of a

Hall sensor area of a magnetic field sensor arrangement according to a third

Embodiment of the present invention, and Fig. 5b) shows a schematic

Top view of the Hall sensor area of the magnetic field sensor arrangement according to the third embodiment of the present invention.

In the third embodiment shown in FIG. 5, a magnetic field flux concentrator region FLC formed of a ferromagnetic material is located above, possibly also below, adjacent to the Hall sensor region HS "in FIG Insulation layer arrangement 10, 11, 12, 13, 14, 15 embedded. Of the

Flux concentrator area FLC is provided in the form of a hollow cylinder with a cavity HL, wherein the cylinder axis is substantially perpendicular to the Hall sensor area HS ".

The preparation of the Flußkonzentratorbereichs FLC is preferably done by a thin-film deposition with the same material as that for the

Magnetic core regions SE1, SE2 of Fluxgatesensoreinrichtungen, so for example Ni / Fe / Al (nickel / iron / aluminum).

For this purpose, in a fourth above the third insulating layer applied

Insulation layer 14 etched a hole and deposited over a Ni / Fe / Al layer and etched back. To isolate the structure upwards here serves a fifth insulating layer 15th

The additional provision of the Flußkonzentratorbereichs FLC causes increased sensitivity of the Hall sensor H "and a lower noise.

Although the present invention has been fully described above with reference to preferred embodiments, it is not limited thereto but is modifiable in a variety of ways.

Of course, it is possible to provide more than just a Hall sensor device with a plurality of Hall sensor regions in the insulation layer arrangement in order to reduce offset by packaging voltages. Also can more

Fluxgatesensoreinrichtungen be provided.

Although in the above embodiments, the Hall sensor areas are substantially parallel to the front side VS, they can by appropriate

Structuring techniques also on inclined planes within the

Insulation layer stack are provided to be made sensitive to magnetic fields in the x, y plane.

The geometries of the embodiments presented above, in particular the geometries of the Hall sensor regions, can be varied as required. Also, the present invention is not limited to the III-V semiconductor material InSb but is applicable to any III-V semiconductor materials which are Hall-sensitive.

In the first embodiment, the magnetic coil devices SE1, SE2 each comprise a first and a second coil device, which serve for excitation or for pick-up. However, it is also possible in the first embodiment, only egg first coil, which serves both for excitation and for pick-up to provide.

Claims

Claims Claims

A magnetic field sensor device comprising: an ASIC substrate (AC; AC) having a front side (VS) and a back side (RS); and a Hall sensor device (H; Η '; H ") which has a Hall sensor region (HS, HS', HS") formed from an III-V semiconductor material which is inserted into an insulation layer arrangement (10, 11) applied to the front side (VS) , 12, 13, 10, 11, 12, 13, 14, 15); wherein the Hall sensor area (HS, HS ', HS ") via a through the

Insulation layer arrangement (10, 11, 12, 13, 10, 11, 12, 13, 14, 15) guided first

Conductor device (L2) is electrically connected to a Hall sensor evaluation circuit means (101) formed in the ASIC substrate (AC; AC).

2. Magnetic field sensor arrangement according to claim 1, wherein the Hall sensor area (HS, HS ', HS ") is formed from InSb (indium antimonide).

3. Magnetic field sensor arrangement according to claim 1 or 2, wherein the Hall sensor area (HS, HS ', HS ") has a layer sequence (S1, SS1, S2, SS2, S3) with material layers of different crystal grain size.

The magnetic field sensor device according to claim 3, wherein first layers (S1, S2, S3) having a first crystal grain size and second layers (SS1, SS2) having a second crystal grain size are alternately formed, wherein the second crystal grain size is substantially smaller than the first crystal grain size.

Magnetic field sensor arrangement according to one of the preceding claims, wherein at least one fluxgate sensor device (F1, F2; F0), which comprises a magnetic core region (FC1, FC2; FCO) formed from a ferromagnetic material, and a magnet coil device (SE1, SE2; SE0) into which on the front side (VS) embedded insulating layer arrangement (10, 11, 12, 13, 10, 11, 12, 13, 14, 15) is embedded; and wherein the magnetic core region (FC1, FC2; FCO) and the magnetic coil device (SE1, SE2; SEO) pass over a second wiring device guided through the insulation layer assembly (10, 11, 12, 13; 10, 11, 12, 13, 14, 15) (L1) is electrically connected to a fluxgate sensor evaluation circuit means (100) formed in the ASIC substrate (AC; AC).

6. The magnetic field sensor arrangement according to claim 5, wherein the Hall sensor device (H; H '; H' ') and the fluxgate sensor device (F1, F2; FO) in different planes of the

Insulating layer arrangement (I0, 11, 12, 13; I0, 11, 12, 13, 14, 15) are embedded.

The magnetic field sensor device according to claim 6, wherein the Hall sensor region (HS ') is disposed above or below adjacent one end (E1) of the magnetic core region (FCO).

Magnetic field sensor arrangement according to one of the preceding claims, wherein a magnetic field flux concentrator region (FLC) formed of a ferromagnetic material above or below adjacent to the Hall sensor region (HS ") in the

Insulation layer arrangement (10, 11, 12, 13, 14, 15) is embedded.

9. Magnetic field sensor arrangement according to claim 8, wherein magnetic field

Flux Concentrator (FLC) is designed as a hollow cylinder whose cylinder axis (ZA) is substantially perpendicular to the Hall sensor area (HS ").

10. Magnetic field sensor arrangement according to one of claims 5 to 9, wherein the

Magnetic core region (FC1, FC2; FCO) and / or the flux concentrator region (FLC)

Ni / Fe / Al (nickel / iron / aluminum) is formed.

1 1. A magnetic field sensor assembly manufacturing method comprising the steps of: providing an ASIC substrate (AC; AC) having a front surface (VS) and a surface

Rear side (RS) with a Hall sensor evaluation circuit device (101) formed in the ASIC substrate (AC; AC);

Embedding a Hall sensor region (HS, HS ', HS ") formed from an III-V semiconductor material into an insulation layer arrangement (10, 11, 12, 13, 10, 11, 12, 13, 14, 15), and electrically connecting the Hall sensor region (HS, HS ', HS ") via a first through the insulating layer arrangement (I0, 11, 12, 13, 10, 11, 12, 13, 14, 15)

Printed conductor device (L2) with a Hall sensor evaluation circuit device (101) formed in the ASIC substrate (AC; AC).

12. Manufacturing method according to claim 11, wherein the Hall sensor area (HS, HS ', HS ") is formed by a layer sequence (S1, SS1, S2, SS2, S3) having

Material layers of different crystal grain size is deposited and then patterned.

The manufacturing method according to claim 11 or 12, wherein the hall sensor area (HS, HS ', HS ") is formed by a sputtering method.

14. A manufacturing method according to claim 11, 12 or 13, wherein the Hall sensor region (HS, HS ', HS ") is formed of InSb (indium antimonide).

15. A method of operating a magnetic field sensor array according to claim 7, wherein said Hall sensor means (H; Η '; H' ') is used to detect a flux change upon excitation of said flux gate sensor means (F1, F2; F0).