Semiconductor device with integrated soft magnetic component and method for producing same

Abstract

A semiconductor device includes a semiconductor substrate, the semiconductor substrate including: an excitation circuit for applying an excitation signal; the soft magnetic assembly is used for guiding the magnetic flux lines; the soft magnetic component is electrically connected to the excitation by means of at least two electrical contacts in the form of a back contact or a side contact; the substrate further comprises at least one electromagnetic transducer, the at least one electromagnetic transducer being operably connected to the soft magnetic assembly; the excitation circuit comprises a modulator used for providing a modulated signal to the soft magnetic assembly to modulate the magnetic conductivity of the soft magnetic assembly; the substrate further includes a demodulator configured to demodulate a signal obtained from the at least one electromagnetic transducer.

Description

Technical Field

[0001] The present invention generally relates to the field of semiconductor devices comprising a semiconductor substrate containing a soft magnetic component and a method for producing such a semiconductor device. Background Art

[0002] Various semiconductor devices including active soft magnetic components or passive soft magnetic components are known in the art. Examples of devices having active soft magnetic components are devices having magnetoresistive (MR) components or devices having magneto-impedance (MI) components. Examples of devices having passive soft magnetic components are integrated fluxgates, integrated transformers, magnetic sensor devices having Hall elements and flux concentrators (IMCs), and the like.

[0003] There is always room for improvement or substitution. Summary of the Invention

[0004] An object of an embodiment of the present invention is to provide a semiconductor device and a method for producing the semiconductor device. The semiconductor device includes a semiconductor substrate including a soft magnetic component.

[0005] An object of embodiments of the present invention is to provide a semiconductor device in which soft magnetic components are used in a non-classical manner, for example for additional functionality and / or for safety purposes.

[0006] An object of an embodiment of the present invention is to provide a semiconductor device having at least two operating modes: a first mode in which the soft magnetic components are used in their normal manner (as known in the art); and a second mode in which the soft magnetic components are used in a non-standard manner for additional functionality and / or for safety purposes.

[0007] These and other objectives are achieved by embodiments of the present invention.

[0008] According to a first aspect, the present invention provides a semiconductor device, which comprises: a semiconductor substrate (e.g., a CMOS substrate), the semiconductor substrate comprising: an excitation circuit for applying an excitation signal (e.g., a current or voltage signal); and a soft magnetic component (e.g., comprising or made of an FeNi alloy) for guiding magnetic flux lines (e.g., of a magnetic field to be measured); wherein the soft magnetic component is electrically connected to the excitation circuit by means of at least two electrical contacts (e.g., E1, S1); wherein the at least two electrical contacts are a back contact located at the bottom surface of the soft magnetic component, or a back contact located at the bottom surface of the soft magnetic component. A side contact portion at a side surface; wherein the semiconductor substrate further includes at least one electromagnetic transducer (for example, at least one Hall element, at least one coil), which is arranged in close proximity to the soft magnetic component and is operably connected to the soft magnetic component; wherein the excitation circuit includes a modulator for providing a modulated signal (for example, a PWM signal, a PSK (phase shift keying) signal, an FM modulated signal, an AM modulated signal) to the soft magnetic component so as to modulate its magnetic permeability; wherein the semiconductor device further includes a demodulator configured to demodulate a signal obtained from the at least one electromagnetic transducer.

[0009] In this embodiment, the soft magnetic component is preferably a passive component during normal operation of the semiconductor device, for example as a sensor device, an integrated transformer, or an integrated fluxgate.

[0010] In this embodiment, the soft magnetic component may be, for example, an integrated flux concentrator (IMC) or integrated fluxgate, or the core of a transformer, which is typically "left floating," or connected to a single potential (eg, ground) during normal operation.

[0011] Figure 9 An example of this embodiment is shown in FIG.

[0012] According to a second aspect, or a further embodiment of the first aspect, the present invention provides a semiconductor device, comprising: a semiconductor substrate (e.g., a CMOS substrate), the semiconductor substrate comprising: an excitation circuit for applying an excitation signal (e.g., a current or voltage signal); and a sensing circuit for measuring a response signal (e.g., a voltage or current signal); and a soft magnetic component (e.g., comprising or made of an FeNi alloy) for guiding magnetic flux lines (e.g., of a magnetic field to be measured); wherein the soft magnetic component is electrically connected to the magnetic field by means of at least two electrical contacts (e.g., E1, E2, S1, S2) are electrically connected to the excitation circuit and electrically connected to the sensing circuit; and wherein at least two electrical contacts are back contacts located at the bottom surface of the soft magnetic component, or side contacts located at the side surface of the soft magnetic component; wherein the excitation circuit includes a modulator for providing a modulated signal (for example, a PWM signal, a PSK (phase shift keying) signal, an FM modulated signal, an AM modulated signal) to the soft magnetic component so as to modulate its magnetic permeability; wherein the semiconductor device further includes a demodulator configured to demodulate the signal obtained from the sensing circuit.

[0013] In this embodiment, the soft magnetic component is preferably an active component during normal operation of the semiconductor device, for example as an MR sensor or as an MI sensor device.

[0014] Figure 10 An example of this embodiment is shown in FIG.

[0015] According to the third aspect, or a further embodiment of the first aspect, the present invention provides a semiconductor device comprising: a semiconductor substrate (e.g., a CMOS substrate), the semiconductor substrate comprising: an excitation circuit for generating an excitation signal (e.g., a current or voltage signal); and a sensing circuit for measuring or detecting a response signal (e.g., a voltage or current signal); and a soft magnetic component (e.g., comprising or made of an FeNi alloy) for guiding magnetic flux lines (e.g., of a magnetic field to be measured); wherein the soft magnetic component is electrically connected to the excitation circuit and electrically connected to the sensing circuit by means of at least two electrical contacts (e.g., E1, S1); wherein the at least two electrical contacts are back contacts located at the bottom surface of the soft magnetic component, or side contacts located at the side surface of the soft magnetic component; wherein the semiconductor device (e.g., the sensing circuit, or a processor circuit connected to the sensing circuit) is configured to detect defects (e.g., mechanical or electrical defects) based on the response signal.

[0016] Figure 7 and Figure 8 An example of this embodiment is shown in FIG.

[0017] In this embodiment, the soft magnetic component may be an active component during normal operation of the semiconductor device, or may be a passive component.

[0018] In an embodiment of the third aspect, the semiconductor substrate further includes at least one electromagnetic transducer (e.g., H1, H2) (e.g., at least one Hall element, at least one coil), which is arranged in close proximity to the soft magnetic component; and the semiconductor substrate further includes an excitation and readout circuit, which is connected to the at least one electromagnetic transducer; and the semiconductor device has a first operating mode, wherein the excitation circuit and the sensing circuit are actively used to detect defects; and the semiconductor device has a second operating mode, wherein the excitation circuit is deactivated and the excitation and readout circuit is used to obtain a signal from the electromagnetic transducer.

[0019] In this embodiment, the soft magnetic component is preferably a passive component during normal operation of the semiconductor device, for example as a sensor device, as a transformer, as an integrated fluxgate. Figure 8 An example of such an embodiment is shown in FIG.

[0020] In one embodiment, the soft magnetic component may serve as the IMC, and the transducer is one or more Hall plates, and the "energizing and readout circuitry" includes "bias and readout" circuitry for the Hall plates.

[0021] In another embodiment, the soft magnetic component can act as an integrated fluxgate, and the transducer is two or more coils, at least one excitation coil and at least one pickup coil, and the "energizing and readout" circuit includes "transmitter circuitry and receiver circuitry" for the coils.

[0022] In an embodiment of the present invention, the at least one electromagnetic transducer is at least one Hall element;

[0023] In an embodiment of the invention, the at least one electromagnetic transducer is at least one coil.

[0024] In an embodiment of the present invention, the semiconductor device may be a sensor device.

[0025] In an embodiment of the present invention, the excitation circuit is configured to apply a voltage (e.g., a dc voltage, an ac voltage, or a combination of a dc voltage and an ac voltage) across the at least two electrical contacts, and the sensing circuit is configured to measure the current flowing through the soft magnetic component.

[0026] In an embodiment of the present invention, the excitation circuit is configured to cause current (e.g., dc current, ac current, or a combination of dc current and ac current) to flow through the soft magnetic component, and the sensing circuit is configured to measure the voltage across the contact.

[0027] In an embodiment of the present invention, the processing circuit may include a programmable processor. The processing circuit may be configured to detect an open circuit between the at least two contacts, for example, by detecting that substantially no current flows through the soft magnetic component, or that the resistance R is greater than a predefined value, or that the magnitude of the electrical impedance |Z| is greater than a predefined value. The processing circuit may further be configured to provide an output signal indicating detection of the defect.

[0028] In an embodiment of the present invention, the semiconductor device may be, for example, a magnetic sensor device, such as a position sensor device, an angle sensor device, a linear sensor device, a proximity sensor device, an integrated fluxgate, or an integrated transformer.

[0029] In an embodiment of the present invention, a semiconductor device may have two operating modes, including: a first mode (e.g., a "normal operating mode"), in which the device performs its normal functions, such as measuring magnetic field values, determining position, converting input voltage and current into output voltage and current, etc.; and a second mode, in which diagnostic tests are performed to verify the electrical and / or mechanical integrity of the device. Such devices are more suitable for applications where "functional safety" is important. During the "normal operating mode," the soft magnetic material may remain electrically floating (e.g., in the case of an integrated fluxgate, transformer, or IMC), or may be provided with a dc signal (e.g., in the case of an MR sensor), or may be provided with an ac signal (e.g., in the case of an MI sensor).

[0030] In an embodiment of the present invention, the semiconductor device may have two operating modes, including: a first mode (e.g., "normal operating mode"), in which the device performs its normal functions, such as measuring magnetic field values, determining position, converting input voltage and current into output voltage and current, etc., and "diagnostic testing" may be one or more additional steps performed during normal operation of the device.

[0031] In an embodiment of the present invention, the excitation circuit may be configured to generate an alternating voltage or an alternating current.

[0032] In embodiments of the present invention, the magnetic component may be arranged on top of the semiconductor substrate, or may be partially or completely embedded in the semiconductor substrate.The magnetic component is preferably a "thin film" component.

[0033] In an embodiment of the present invention, the semiconductor substrate includes a polyimide layer, and the magnetic component is disposed on top of the polyimide layer.

[0034] In an embodiment of the invention, the magnetic component is provided on top of and in electrical contact with the conductive seed layer.Preferably, the magnetic component is provided at least in part using electroplating.

[0035] In an embodiment according to the first aspect, the semiconductor device may optionally further include a modulator and a demodulator (e.g., as specified in an embodiment according to the second aspect or the third aspect), and / or at least one electromagnetic transformer (e.g., as specified in an embodiment according to the third aspect).

[0036] In an embodiment according to the second aspect, the semiconductor device may optionally further include one or more electromagnetic transducers (e.g., one or more Hall elements or coils), and if these transducers are read out when a modulated signal is applied to the soft magnetic component, the signals obtained from these transducers need to be demodulated.

[0037] In embodiments according to the third aspect, the semiconductor device may optionally be further configured to perform the “diagnostic test” described in embodiments according to the first aspect, for example by testing whether the soft magnetic component provides a closed circuit or an open circuit between at least two contacts.

[0038] In embodiments of the present invention, semiconductor devices may be further configured to perform resistance or impedance measurements. The latter involves determining the attenuation and phase shift between an excitation signal and a sensed signal (e.g., between an applied voltage and a sensed current, or between an applied current and a sensed voltage). Impedance values can be represented by complex values having a real part and a non-zero imaginary part.

[0039] In an embodiment of the present invention, the semiconductor device is an integrated circuit (a so-called "chip") encapsulated in a molded package.

[0040] In a preferred embodiment of the invention, the semiconductor substrate is overmolded in such a way that the soft magnetic elements are not exposed (after molding) and are not directly accessible from outside the molded package.

[0041] In an embodiment of the present invention, the soft magnetic material is a ferromagnetic material, such as FeNi or Fe-Ni alloy.

[0042] In a preferred embodiment of the present invention, the semiconductor substrate consists essentially of silicon.

[0043] In a preferred embodiment of the present invention, the semiconductor substrate (excluding the soft magnetic components) is a "CMOS device", ie, is produced using a CMOS compatible process.

[0044] In an embodiment of the invention, the processing circuit may be or may include a programmable digital processor.

[0045] In an embodiment of the present invention, the semiconductor substrate further includes a non-volatile memory operatively connected to the processing circuit. The non-volatile memory may store at least one constant, or may store a lookup table for converting the measured impedance value into a magnetic field value, a current value, a torque value, etc.

[0046] In an embodiment according to the third aspect, the excitation circuit is electrically connected to the soft magnetic component at first and second excitation contacts (e.g., E1, E2); and the sensing circuit is electrically connected to the soft magnetic component at first and second sensing contacts (e.g., S1, S2).

[0047] In an embodiment of the present invention, the excitation circuit is configured to apply an alternating voltage to the soft magnetic element, so as to cause an alternating current to flow through at least a portion of the soft magnetic element.

[0048] In an embodiment of the invention, the excitation circuit is configured for passing an alternating current through the soft magnetic element and for measuring an alternating voltage across at least a portion of the soft magnetic element.

[0049] In an embodiment of the present invention, the excitation circuit can be configured to apply an AC voltage or AC current with a frequency in the following range: from 10kHz to 2.0GHz, or from 10kHz to 500MHz, or from 100kHz to 200MHz, or from 10kHz to 100MHz, or from 50kHz to 500MHz, or from 100kHz to 100MHz, or from 50kHz to 50MHz.

[0050] In an embodiment of the invention, the sensing circuit is configured for measuring an alternating voltage or for measuring an alternating current flowing through at least a portion of the soft magnetic element.

[0051] In an embodiment of the present invention, the first excitation contact (eg, E1 ) coincides with the first sensing contact (eg, S1 ), and the second excitation contact (eg, E2 ) coincides with the second sensing contact (eg, S2 ).

[0052] In an embodiment of the present invention, the first sensing contact and the second sensing contact (eg, S1 , S2 ) are located between the first excitation contact and the second excitation contact (eg, E1 , E2 ).

[0053] In embodiments of the invention, the energizing contact may be positioned at least 5% or at least 10% or at least 15% of the length of the elongated portion of the MI element from the longitudinal end of the MI element.

[0054] In an embodiment of the present invention, the semiconductor substrate further includes a buffer layer (eg, a polyimide layer), and the soft magnetic component is arranged on top of the buffer layer.

[0055] The advantage of the buffer layer is that it reduces mechanical stress.

[0056] In an embodiment of the present invention, the excitation circuit and the sensing circuit are electrically connected to the soft magnetic component by means of electrical interconnections through the buffer layer.

[0057] The advantage lies in electrically connecting the soft magnetic component "from below", which can be called a "bottom contact" or "back contact", because by doing so the additional processing step of connecting the soft magnetic component "from above" (for example, by means of bonding wires) can be avoided, and because it is mechanically more stable.

[0058] In an embodiment of the present invention, the soft magnetic component has a substantially planar shape, and its thickness T is at least 500 nm, or at least 600 nm, or at least 700 nm, or at least 800 nm, or at least 900 nm, or at least 1.0 μm, or at least 1.2 μm, or at least 1.4 μm, or at least 1.6 μm, or at least 1.8 μm, or at least 2.0 μm, or at least 2.5 μm, or at least 3.0 μm, or at least 3.5 μm, or at least 4.0 μm, or at least 4.5 μm, or at least 5.0 μm, or at least 6.0 μm, or at least 7.0 μm, or at least 8.0 μm, or at least 9.0 μm, or at least 10.0 μm, or at least 12.0 μm, or at least 14.0 μm, or at least 16.0 μm, or at least 18.0 μm, or at least 20.0 μm.

[0059] In an embodiment of the invention, the soft magnetic component is at least partially deposited on top of the conductive seed layer by electroplating.The seed layer may be deposited on top of the polyimide layer.

[0060] In an embodiment of the invention, the soft magnetic component has a substantially planar shape with a predominantly circular top view and a diameter in the range from 100 μm to 300 μm (eg in the range from 150 μm to 250 μm).

[0061] In an embodiment of the present invention, the soft magnetic component has a substantially planar shape, having a top view that is primarily elliptical, or a top view that is primarily square, or a top view that is primarily rectangular, having a length L and a width W, wherein W≤L, and W / L is at least 0.25 or at least 0.35 or at least 0.40 or at least 0.45 or at least 0.50.

[0062] In an embodiment of the present invention, the semiconductor device further comprises a biasing device for generating a DC magnetic field in the soft magnetic component.

[0063] This embodiment provides the advantage that the characteristic of the impedance with respect to the magnetic field to be measured can be deviated from the origin, and the sensitivity can be improved.

[0064] In an embodiment of the present invention, the biasing means comprises a coil, for example a planar coil, implemented in a so-called "metal stack" or "interconnect stack" of a semiconductor device (for example a CMOS device). The coil may comprise one, two or three metal layers. The biasing coil may be implemented, for example, in a manner similar to the transmitter coil described in EP3961926 (A1) and may be arranged in a manner similar to the transmitter coil described in EP3961926 (A1). Figure 8 (a) to Figure 8 (d), which is incorporated herein by reference in its entirety, but in the current application, DC current is preferably supplied.

[0065] In an embodiment of the present invention, the soft magnetic component has a cross-section with rounded or truncated edges or corners, obtained, for example, by etching.

[0066] In an embodiment of the present invention, the semiconductor substrate further includes two soft magnetic trapezoidal shapes disposed near opposite ends (eg, A, B) of the soft magnetic element.

[0067] In other words, the elongated portion of the soft magnetic component is arranged between the two trapezoidal shapes.

[0068] The trapezoidal shape can be integrally formed with the soft magnetic element, in which case the elongated shape contacts the trapezoidal shape. In this case, preferably, the trapezoidal shape has the same thickness as the soft magnetic element. The electrical contacts for the excitation circuit and the sensing circuit can be located on the trapezoidal shape, or on the elongated portion, or the excitation contacts can be located on the trapezoidal shape and the sensing contacts can be located on the elongated portion.

[0069] Alternatively, the trapezoidal shape is spaced apart from the elongated portion of the soft magnetic element, in which case there is a smaller distance between the elongated portion and the trapezoidal shape.

[0070] The advantage of this embodiment is that the trapezoidal section acts as a magnetic flux concentrator and the magnetic field component Bx is passively amplified, which further improves the sensitivity of the magneto-impedance measurement, and does so in a passive manner (i.e. without additional power consumption). This is a major advantage, especially for portable applications such as the eCompass.

[0071] In an embodiment of the present invention, the soft magnetic component has a circular shape; and the semiconductor substrate includes a plurality of at least two (or at least three, or at least four, or at least six, or at least eight) horizontal Hall elements arranged near the periphery of the soft magnetic component; and the soft magnetic component is electrically connected to the semiconductor substrate by means of a plurality of at least two (or at least three, or at least four, or at least six, or at least eight) electrical contacts (c1, c2).

[0072] The number of horizontal Hall elements may be equal to the number of electrical contacts, but that is not absolutely necessary.

[0073] The electrical contacts can be arranged so that they are located on a virtual circle whose radius is less than the radius of the soft magnetic component. Preferably, the radius of the virtual circle on which the contacts are located is at least 50%, or at least 60%, or at least 70%, or at least 80%, or at least 90% of the radius of the soft magnetic component.

[0074] The electrical contact portion may be located on a virtual line segment extending in a radial direction from the center of the soft magnetic component to the corresponding Hall element.

[0075] The electrical contact may also be located on an imaginary line segment extending in a radial direction from the center of the soft magnetic component to a position between two adjacent Hall elements (ie, angularly offset from the angular position of the Hall elements).

[0076] In an embodiment, one of the contacts is used to provide an excitation signal and each of the other contacts is sensed individually in order to detect defects, eg mechanical defects (such as, for example, broken components, delamination, peeling).

[0077] In an embodiment of the present invention, the semiconductor device further includes a second soft magnetic component (e.g., IMC2); wherein the first soft magnetic component (e.g., IMC1) includes at least a first electrical contact and a second electrical contact (e.g., c1, c2); wherein the second soft magnetic component (e.g., IMC2) includes at least a third electrical contact and a fourth electrical contact (e.g., c3, c4); and wherein the second electrical contact (e.g., c2) is electrically connected to the third electrical contact (e.g., c3) in the semiconductor substrate; and wherein an excitation signal is applied to the first electrical contact (e.g., c1), and the sensed signal is obtained from the fourth electrical contact (e.g., c4).

[0078] exist Figure 17A and Figure 17B The figure in the middle shows an example of this embodiment. This semiconductor device can detect defects (e.g., missing or broken) in any of the soft magnetic components in the "chain." More than two soft magnetic components can be interconnected in the same way. An advantage of this embodiment is that the test circuit only requires a single excitation node and a single sensing node.

[0079] According to a fourth aspect, the present invention also provides a method for producing a semiconductor substrate, comprising the following steps: a) providing a semiconductor substrate (e.g., a CMOS substrate), which includes an electronic circuit system, which includes at least an excitation circuit and a processing circuit; b) optionally providing a buffer layer (e.g., a polyimide layer) on top of the semiconductor substrate; c) making at least two openings through the upper layer of the semiconductor substrate (e.g., a protective layer or a buffer layer) to form an excitation contact portion and / or a sensing contact portion electrically connected to the circuit system; d) optionally providing at least one seed layer of a conductive material (e.g., Cu) (e.g., by sputtering); e) providing a soft magnetic material (e.g., a thin film of ferromagnetic material (e.g., FeNi or an Fe-Ni alloy)), for example on top of the seed layer (if present), preferably by sputtering and / or by electroplating.

[0080] In an embodiment of the present invention, the method may further include one or more of the following features:

[0081] Wherein, the semiconductor substrate provided in step a) is a CMOS substrate;

[0082] Wherein, the semiconductor substrate provided in step a) further comprises at least two horizontal Hall elements, and bias and readout circuits;

[0083] Wherein, the method further comprises: providing at least one seed layer of a conductive material (e.g., Cu) (e.g., by sputtering);

[0084] Wherein, the semiconductor substrate provided in step a) further comprises a buffer layer on top of the semiconductor substrate;

[0085] Further comprising the steps of: wet etching or anisotropic etching after applying the soft magnetic material to provide rounded or truncated ends and / or edges;

[0086] Wherein, the method further comprises step f): annealing the soft magnetic material while applying a static magnetic field oriented in a direction parallel to the semiconductor substrate (2136);

[0087] Therein, the method further comprises the step of creating an easy axis of magnetization by passing a relatively large current through the soft magnetic component during a predefined time.

[0088] According to the fifth aspect, the present invention also provides a process control method, which can be used during the production of a semiconductor substrate comprising a soft magnetic material (for example, as specified in the first, second or third aspect mentioned above), wherein the process control method includes the following steps: i) generating a test voltage by a test system outside the semiconductor substrate and applying the test voltage to a voltage node connected to the back contact or side contact of the soft magnetic component; ii) measuring the resulting test current caused by the test voltage by the test system; iii) testing whether the resulting test current is less than a first predefined threshold and / or greater than a second predefined threshold, and detecting a problem based on the results of the one or more comparisons.

[0089] Advantageously, these steps can be performed by a test system external to the semiconductor substrate under test.Step iii) can be performed on a digital processor of such a test system, such test system being external to the semiconductor substrate.

[0090] According to a sixth aspect, the present invention also relates to a test system that can be operably connected to a semiconductor device comprising soft magnetic material (for example, as specified in the first, second or third aspect) and is configured to perform the method of process control according to the fifth aspect.

[0091] Particular and preferred aspects of the invention are set out in the accompanying independent and dependent claims. Features from the dependent claims may be combined with features of the independent claims and with features of other dependent claims as appropriate, and not merely as explicitly set out in the claims.

[0092] These and other aspects of the invention will be apparent from and elucidated with reference to the embodiment(s) described hereinafter. BRIEF DESCRIPTION OF THE DRAWINGS

[0093] Figure 1 An embodiment of a semiconductor substrate having a soft magnetic component, such as a magneto-impedance (MI) element integrally formed on top of the semiconductor substrate, is shown in accordance with an embodiment of the present invention.

[0094] Figure 2 The embodiment according to the present invention is shown Figure 1 A variation of the embodiment wherein the first sensing contact coincides with the first actuating contact, and wherein the second sensing contact coincides with the second actuating contact.

[0095] Figure 3An embodiment of a semiconductor substrate as another embodiment of the present invention is shown, which has a soft magnetic component and an electromagnetic transducer arranged near the end of the soft magnetic component or near the periphery of the soft magnetic component, as well as a circuit system for applying a modulated signal to the soft magnetic component, and a circuit system for reading and demodulating the signal obtained from the electromagnetic transducer.

[0096] Figure 4 Shown Figure 3 A variation of the embodiment further includes a sensing circuit for using the soft magnetic component as an active component (e.g., an MI element). A demodulator can be used to demodulate the signal obtained from the sensing circuit and / or to demodulate the signal obtained from the readout circuit.

[0097] Figure 5 Shown is a semiconductor substrate, for example a CMOS substrate, with electronic circuitry (not shown) and with a soft magnetic component electrically connected to the circuitry via a "back contact" or "bottom contact".

[0098] Figure 6 Shown is a semiconductor substrate, for example a CMOS substrate, with electronic circuitry (not shown) and with soft magnetic components, which are electrically connected to the circuitry via "side contacts".

[0099] Figure 7 is a schematic representation of a semiconductor device having a soft magnetic component, and an excitation circuit and a sensing circuit configured to detect defects (e.g., fracture or (partial) peeling) of the soft magnetic component (e.g., in a diagnostic mode).

[0100] Figure 8 Shown Figure 7 A variant further includes one or more electromagnetic transducers (e.g., Hall elements or coils) arranged adjacent to the soft magnetic component and operably connected to the soft magnetic component.

[0101] Figure 9 Shown Figure 8 A variant of , wherein the sensing contact coincides with the excitation contact, and the semiconductor device further comprises a modulator for modulating the magnetic permeability of the soft magnetic material, and a demodulator for demodulating signals obtained from the one or more electromagnetic transducers.

[0102] Figure 10 Shown Figure 8 Another variation of the method further includes a modulator for modulating the magnetic permeability of the soft magnetic material, and a demodulator for demodulating the signal obtained from the sensing circuit.

[0103] Figure 11 (a) shows Figure 8a top view of an example or variation of , and Figure 11 (b) shows Figure 8 A side view of an example or variation of a device in which the sensing contact coincides with the excitation contact, and wherein the soft magnetic component is a magnetic induction (MI) element having an elongated shape extending in the X direction, and wherein two horizontal Hall elements are positioned near longitudinal ends of the MI element.

[0104] Figure 12 (a) shows Figure 11 (a) and Figure 11 (b) is a top view of a variant of the invention, and Figure 12 (b) shows Figure 11 (a) and Figure 11 (b) Side view of a variation in which the soft magnetic component is an integrated passive flux concentrator (IMC) having a disk shape, and in which two horizontal Hall elements are positioned near the periphery of the IMC.

[0105] Figure 13 Yes Figure 12 (a) and Figure 12 A simplified representation of the semiconductor device illustrated in (b) or a variation thereof, having two electrical contacts and two horizontal Hall elements angularly spaced apart by 180°.

[0106] Figure 14 Shown Figure 13 A variant in which the electrical contact is also positioned at a second radius smaller than the first radius, but the angular position of the electrical contact is angularly offset from the angular position of the horizontal Hall element.

[0107] Figure 15 Shown Figure 13 Another variation of , wherein four horizontal Hall elements are arranged near the periphery of the disk-shaped soft magnetic component, and wherein four electrical contacts are arranged in close proximity to corresponding Hall elements.

[0108] Figure 16 Shown Figure 15 A variant in which the positions of the four electrical contacts are angularly offset relative to the position of the Hall element, in this example by 45°.

[0109] Figure 17A shows a top view of an illustrative semiconductor substrate having two soft magnetic components spaced apart from each other, and Figure 17B Shown is a side view of an illustrative semiconductor substrate having two soft magnetic components spaced apart from each other.

[0110] Figure 18 is a schematic representation of a semiconductor substrate including a passive soft magnetic component in the form of an integrated fluxgate.

[0111] Figure 19 A semiconductor substrate with a soft magnetic structure is shown, comprising a central disk and twelve radially oriented segments which are angularly spaced apart by multiples of 360° / 12=30°.

[0112] Figure 20 Shown Figure 19 A variation in which the Hall element is located near the inner end of the radially oriented segment.

[0113] Figures 21 to 23 A flow chart of a method for producing a semiconductor substrate having a soft-magnetic component which is connected to a circuit system of the semiconductor substrate by means of a back contact or a side contact is shown.

[0114] These figures are schematic and non-limiting. In the figures, for illustrative purposes, the size of some elements may be exaggerated and not drawn to scale. Any reference numerals in the claims should not be construed as limiting the scope. The same reference numerals in different figures refer to the same or similar elements. DETAILED DESCRIPTION

[0115] The present invention will be described with respect to particular embodiments and with reference to certain drawings but the invention is not limited thereto but only by the claims.

[0116] The terms first, second, etc. in the specification and claims are used to distinguish between similar elements and not necessarily to describe a sequence in time, space, ranking, or in any other manner. It is to be understood that the terms so used are interchangeable under appropriate circumstances, and that the embodiments of the invention described herein are capable of operation in a sequence different from that described or illustrated herein.

[0117] The terms top, bottom, etc. in the description and claims are used for descriptive purposes and are not necessarily used to describe relative positions. It is understood that the terms so used are interchangeable under appropriate circumstances, and that the embodiments of the invention described herein are capable of operation in orientations other than those described or illustrated herein.

[0118] It should be noted that the term "comprising" as used in the claims should not be interpreted as being limited to the means listed thereafter; it does not exclude other elements or steps. Thus, the term should be interpreted as specifying the presence of the stated features, integers, steps, or components as mentioned, but does not exclude the presence or addition of one or more other features, integers, steps, or components, or groups thereof. Thus, the scope of the expression "a device comprising means A and B" should not be limited to a device consisting solely of components A and B. This means that for the present invention, the only relevant components of the device are A and B.

[0119] Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment, but may. Furthermore, in one or more embodiments, the particular features, structures, or characteristics may be combined in any suitable manner, as would be apparent to one of ordinary skill in the art from this disclosure.

[0120] Similarly, it should be appreciated that in the description of exemplary embodiments of the present invention, various features of the present invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. However, this method of disclosure should not be interpreted as reflecting an intention that the claimed invention requires more features than those expressly recited in each claim. On the contrary, as reflected in the appended claims, inventive aspects lie in fewer features than all of the features of a single preceding disclosed embodiment. Thus, the claims appended to the detailed description are hereby expressly incorporated into this detailed description, with each claim itself representing a separate embodiment of the present invention.

[0121] Furthermore, although some embodiments described herein include some features included in other embodiments but do not include other features included in those other embodiments, the combination of features of different embodiments is intended to fall within the scope of the present invention and form different embodiments as would be understood by those skilled in the art. For example, in the appended claims, any of the claimed embodiments may be used in any combination.

[0122] In the description provided herein, numerous specific details are set forth. However, it should be understood that embodiments of the present invention may be practiced without these specific details. In other instances, well-known methods, structures, and techniques are not shown in detail to avoid obscuring an understanding of this specification.

[0123] In this document, unless explicitly mentioned otherwise, the term "magnetic sensor device" refers to a device that is preferably integrated in a semiconductor substrate and includes at least one "magnetic sensor" or at least one magnetic "sensor element". The sensor device can be included in a package (also called a "chip"), but that is not absolutely necessary.

[0124] In this document, the term "magnetic sensor element" or "magnetic sensor" may refer to a component or a group of components or subcircuits or structures capable of measuring magnetic quantities, such as, for example, a magnetoresistive (MR) element, a GMR element, an XMR element, a horizontal Hall plate, a vertical Hall plate, a Wheatstone bridge comprising at least one (but preferably four) magnetoresistive elements, a magneto-impedance (MI) element, a giant magneto-impedance (GMI) element, etc. or a combination thereof.

[0125] In embodiments of the present invention, the term “magnetic sensor structure” may refer to a single “magnetic sensor element” or to an arrangement comprising at least two “magnetic sensor elements” (e.g., one or more horizontal Hall elements) and, optionally, one or more integrated magnetic flux concentrators (IMCs).

[0126] In this document, the expressions "in-plane component of the magnetic field vector" and "projection of the magnetic field vector in the sensor plane" are used synonymously. If the sensor device is or includes a semiconductor substrate, this also means "component of the magnetic field parallel to the semiconductor plane." These components may be labeled Bx and By.

[0127] In this document, the expressions "out-of-plane component of the magnetic field vector" and "Z component of the vector" and "projection of the vector onto an axis perpendicular to the sensor plane" mean the same thing. This component may be denoted Bz.

[0128] Embodiments of the present invention are typically described using an orthogonal coordinate system fixed to the sensor device and having three axes X, Y, Z, where the X and Y axes are parallel to the substrate and the Z axis is perpendicular to the substrate.

[0129] In this document, the expressions “magneto-impedance component” or “magneto-impedance element” are used as synonyms.

[0130] In this document, the expressions "spatial derivative" or "derivative" or "spatial gradient" or "gradient" are used as synonyms. If the order of the derivative is not explicitly mentioned, a first-order gradient is meant, unless this is clear from the context. In the context of the present invention, a gradient is typically determined as the difference between two values measured at two locations spaced apart along a certain direction. In theory, the gradient is typically calculated as the difference between the two values divided by the distance between the sensor locations, but in practice, the division by the distance is often omitted because the measured signal needs to be scaled anyway. Therefore, in the context of the present invention, the expressions "magnetic field difference" and "magnetic field gradient" can be used interchangeably.

[0131] In this application, horizontal Hall plates are typically referred to as H1, H2, etc., and signals obtained from horizontal Hall plates are typically referred to as h1, h2, etc., vertical Hall plates are typically referred to as V1, V2, etc., and signals obtained from vertical Hall plates are typically referred to as v1, v2, etc.

[0132] The expression "soft magnetic material" is well known in the field of magnetic materials. Soft magnetic materials are materials that are easily magnetized and demagnetized. They may typically have a magnetic field strength of less than 1000 Am -1 (For example, at 0.1Am -1 with 10Am -1 They are mainly used to enhance and / or channel flux.

[0133] A "soft magnetic component" refers to a component or element composed of or primarily including a soft magnetic material, such as an element made of an FeNi alloy. Unless explicitly mentioned otherwise, a "soft magnetic component" can be used as a magnetoresistive (MR) element, a magneto-impedance (MI) element, a passive magnetic flux concentrator (e.g., an IMC or transformer core), or an integrated fluxgate.

[0134] The "back contacts" may also be referred to as "bottom contacts". They are located at the bottom surface of the soft magnetic component (e.g. Figures 1 to 4 and Figure 5 The “side contact portion” is located near the side surface of the soft magnetic component (e.g., as shown in FIG. Figure 6 ).

[0135] The present invention relates to the field of semiconductor devices, which include a semiconductor substrate (e.g., a CMOS substrate) including a soft magnetic component, meaning a piece of soft magnetic material, for example, including or consisting of FeNi or a nickel-iron alloy. In the context of the present invention, the soft magnetic component is a "thin film material", preferably having a thickness T in the range of from about 500 nm to about 20.0 μm, which is deposited on the semiconductor substrate or partially embedded in the semiconductor substrate. The soft magnetic component has a substantially planar shape, preferably a solid shape (i.e., completely filled, rather than a hollow object).

[0136] Semiconductor devices including active soft magnetic components (i.e., where the soft magnetic components are electrically connected to the circuit system) or semiconductor devices including passive soft magnetic components (i.e., where the soft magnetic components remain floating) are known in the art. Examples of devices having active soft magnetic components are devices having magnetoresistive (MR) components or devices having magneto-impedance (MI) components.

[0137] Examples of devices with passive soft magnetic components are integrated fluxgates, integrated voltage and current transformers, magnetic sensor devices with Hall elements and flux concentrators (IMC).

[0138] As used herein, the "normal function" or "standard function" of an MR element is to measure (directly or indirectly) the resistance of the MR element in the presence of a magnetic field, which resistance changes due to the magnetoresistive effect and is indicative of a characteristic of the magnetic field.

[0139] As used herein, the "normal function" or "standard function" of a MI element is to measure the electrical impedance of the MI element in the presence of a magnetic field (directly or indirectly), which impedance changes due to the skin effect and is indicative of a characteristic of the magnetic field.

[0140] As used herein, the “normal function” or “standard function” of a passive soft magnetic material (such as, for example, an integrated magnetic concentrator (IMC) positioned near a Hall element, or a magnetic core positioned near one or more coils) is to guide magnetic flux lines.

[0141] Circuits for interfacing MR elements, MI elements, horizontal Hall elements, vertical Hall elements, and coils (i.e., circuits for providing energy signals to the MR elements, MI elements, horizontal Hall elements, vertical Hall elements, and coils), and circuits for obtaining readout signals from such elements are known in the art, are not the primary focus of the present invention, and therefore need not be described in further detail here.

[0142] Figure 1 Shown is a cross section of a semiconductor substrate 100 and a magneto-impedance element 111 integrally formed on top of the semiconductor substrate 100. The magneto-impedance element 111 is also referred to herein as an MI element or an MI component.

[0143] Figure 1 The MI element 111 has an elongated shape extending in a first direction X parallel to the semiconductor substrate. The X direction is also referred to as the "longitudinal direction." A second axis Y (also referred to herein as the "lateral direction" or "width direction") is oriented parallel to the substrate 100 and perpendicular to the X axis. A third axis Z (also referred to herein as the "height direction") is oriented perpendicular to the substrate 100.

[0144] In a preferred embodiment, semiconductor substrate 100 (without the MI element) is a "CMOS device," i.e., produced using a CMOS-compatible process. Semiconductor substrate 100 includes an excitation circuit 101 and a sensing circuit 102 for (directly or indirectly) measuring the magneto-impedance effect of MI element 111. Such circuits are known in the art, are not the primary focus of the present invention, and therefore do not require detailed explanation here. Suffice it to say that excitation circuit 101 can be configured to generate an alternating voltage signal or a pulsed voltage signal (e.g., a sinusoidal voltage signal with a predefined amplitude and a predefined frequency), or to generate an alternating current signal or a pulsed current signal (e.g., a sinusoidal current signal with a predefined amplitude and a predefined frequency). The frequency can be in the range of 10 kHz to 2.0 GHz, or in the range of 10 kHz to 500 MHz, or from 100 kHz to 200 MHz, or from 10 kHz to 100 MHz, or from 50 kHz to 500 MHz, or from 100 kHz to 100 MHZ, or from 50 Hz to 50 MHz.

[0145] The semiconductor substrate 100 may further include a processing circuit ( Figure 1 Not explicitly shown in , but see e.g. Figures 7 to 10 ), the processing circuit is connected to the sensing circuit 102 and is configured to provide a signal indicative of the measured impedance or a value derived therefrom, such as the amplitude of the magnetic field component Bx, a current value, a torque value, a linear or angular position, a distance value, etc.

[0146] According to the basic principle of the present invention,

[0147] The MI element 111 mainly includes or is made of a soft magnetic material, such as a ferromagnetic material (e.g., FeNi or Fe-Ni alloy);

[0148] The MI element 111 is arranged (e.g., deposited) on top of the semiconductor substrate 100 (e.g., directly on top of the semiconductor substrate), or on top of a buffer layer 104 (e.g., a polyimide layer). Typically, multiple openings need to be made in the CMOS substrate, and if a buffer layer 104 is also present, multiple openings also need to be made in the buffer layer (e.g., by etching). The MI element 111 can be applied by sputtering and / or by electroplating. The "metal stack" (not explicitly shown) of the CMOS substrate can include multiple patterned metal layers (typically four layers) separated by silicon dioxide (SiO2). The metal stack can further include a conductive "seed layer" that serves both as an etch stop and as a basis for growing soft magnetic material. Alternatively, the seed layer can be sputtered on top of the CMOS substrate. The size of the MI element 111 can be defined by a photolithographic process. The thickness of the MI element 111 can be defined by the duration of the sputtering or electroplating step, or in other suitable ways. It should be noted that the seed layer is only required when the soft magnetic material is deposited by electroplating, but the present invention is not limited thereto. If the soft magnetic material is deposited only by sputtering, the seed layer can be omitted.

[0149] The MI element 111 is electrically connected to the excitation circuit 101 and to the sensing circuit 102 by means of at least two (e.g. only two or four) electrical contacts E1, S1, E2, S2. Figure 1 In the embodiment, these contacts are located at the bottom side of the MI element 111, in which case they are also referred to herein as "back contacts" or "bottom contacts" (see for possible implementations Figure 5 and Figure 22 ), but the present invention is not limited thereto, and it is also possible to connect the MI element to the excitation circuit and the sensing circuit via a "side contact" (for possible implementations see Figure 6 and Figure 23 ). In this way, electrical connections at the top (e.g. by means of bonding wires) can be avoided, whereby additional processing steps can be avoided. In addition, the "back contact" or "side contact" also provides a very strong mechanical anchoring of the MI element, so that the risk of delamination is greatly reduced.

[0150] The semiconductor substrate 100 with the MI element 111 may be mounted on a leadframe (not shown) and / or may be overmolded by a molding compound (not shown) to form a packaged sensor device, also referred to as a “chip”.

[0151] Figure 1The excitation circuit 101 is electrically connected to the MI element 111 by means of two "bottom contacts" or "back contacts" E1, E2 spaced apart by a first non-zero distance in the X direction. The sensing circuit 102 is electrically connected to the MI element 111 by means of two "bottom contacts" or "back contacts" S1, S2 spaced apart by a second non-zero distance in the X direction. The second distance may be less than the first distance, or may be equal to the first distance, for example, in the case where the excitation contacts and the sensing contacts coincide (e.g., as Figure 2 ). The second distance may be at least 150 μm, or at least 200 μm, or at least 250 μm, or at least 300 μm, or at least 400 μm, or at least 500 μm, or at least 750 μm, or at least 1000 μm.

[0152] exist Figure 1 In the example shown, the sensing contacts S1 and S2 are positioned between the excitation contacts E1 and E2, but this is not absolutely necessary, as the sensing contact S1 and the excitation contact E1 can overlap. Similarly, the sensing contact S2 and the excitation contact E2 can overlap. Thus, the MI element 111 can have two back contacts or side contacts (if S1 overlaps with E1 and S2 overlaps with E2), or three back contacts or side contacts (for example, if S1 overlaps with E2, but S2 does not overlap with E2), or four back contacts and side contacts (for example, if S1 and E1 are separate contacts and S2 and E2 are separate contacts).

[0153] The excitation contacts E1 and E2 may be offset in the longitudinal direction from the outer ends A and B of the soft magnetic element 111, for example, by at least L*3%, or at least L*5%, or at least L*10%, or at least L*15%, where L is the length of the MI element in the longitudinal direction. In this way, the risk of uneven current density due to side effects and / or surface defects near the edges or outer ends of the MI structure can be reduced or avoided.

[0154] The MI element 111 may be beam-shaped, having a length L in the X direction (longitudinal direction), a width W in the Y direction (lateral direction), and a height H in the Z direction (height direction).

[0155] In an embodiment, at least one of the ratios L / W and T / W is a value in the range from 5 to 20, such as in the range from 8 to 18, such as in the range from 10 to 15.

[0156] In some embodiments, the ratios L / W and T / W are both in the range from 5 to 20. This is beneficial for the skin effect and thereby for impedance measurements.

[0157] Figure 21 The software will be used to produce Figure 1 A method for a sensor device having a semiconductor substrate as illustrated in FIG.

[0158] Figure 1 The MI element can be used in its "normal way" (e.g. by passing a known current through the MI element, injected via the excitation contact E1 and extracted via the contact E2, and by measuring the voltage across the sense contacts S1, S2). To the best of the inventors' knowledge, integrated MI elements with back or side contacts are not known in the art.

[0159] In a variant (not shown), the MI element 211 has rounded or truncated ends and / or has rounded or truncated edges. This can be achieved, for example, by wet etching. By providing rounded or truncated edges and / or rounded or truncated ends, discontinuities in current density near the periphery of the MI element can be avoided, which can be beneficial for the MI effect.

[0160] The inventors have also contemplated that the sensed signal can also be used to verify whether the soft magnetic component is (still) present, broken, or flaked. This can be achieved, for example, by testing whether the measured current is above a predefined threshold. In fact, this diagnostic test is very useful as a safety check not only for MI elements but also for other soft magnetic components, as will be described further below.

[0161] Figure 2 Shown as Figure 1 A semiconductor substrate 200 of a variant of , wherein the first sensing contact S1 coincides with the first excitation contact E1 , and wherein the second sensing contact S2 coincides with the second excitation contact E2 . All other contents described above also apply here.

[0162] Figure 3 A semiconductor substrate 300 is shown, which has a soft magnetic component 311 and an electromagnetic transducer (in Figure 3 In the example of: two horizontal Hall elements H1, H2), and a circuit system 301 for applying a modulated signal to a soft magnetic component 311, and a circuit system 307 for reading and demodulating the signal obtained from the electromagnetic transducers H1, H2, the electromagnetic transducer (in Figure 3 In the example of FIG, two horizontal Hall elements H1 and H2 are arranged near the ends of the (e.g., elongated) soft magnetic component 311 or near the periphery of the (e.g., circular) soft magnetic component 311. In this embodiment, the soft magnetic component 311 is mainly used to guide flux lines, but its magnetic permeability varies.

[0163] The modulation circuit 301 can generate a modulated signal, such as a voltage or current signal in the form of a sine wave with a predefined amplitude and frequency, or a square wave with a predefined amplitude and frequency, or a PWM signal (pulse width modulation) with a predefined duty cycle, a predefined amplitude and a predefined period, or another type of modulation. In this way, the magnetic permeability of the soft magnetic component 311 can be changed.

[0164] The readout circuit 307 with a demodulator is configured for demodulating the signal obtained from the transducer (eg Hall elements H1 , H2 ). Preferably, the demodulation is synchronized with the modulation, for example using the same clock reference (not explicitly shown).

[0165] In an embodiment, the modulation is not fixed, but rather one or more of, for example, the frequency, amplitude, duty cycle, direct current (dc) component of the modulation signal is varied.

[0166] Figure 4 shows what can be considered Figure 3 The semiconductor substrate 400 of the variant further includes a sensing circuit 402 for measuring and demodulating a response signal obtained from a soft magnetic component 411. The soft magnetic component can be designed (material, shape and size) as an MR element or an MI element, for example.

[0167] In an embodiment, the readout circuit 407 and the Hall elements H1 and H2 are omitted.

[0168] In an embodiment, there is a readout circuit 407 and Hall elements H1, H2, and the same soft magnetic component 411 also serves as a flux guide for guiding flux lines to the electromagnetic transducers H1, H2 (e.g., horizontal Hall elements). The Hall elements H1, H2 can be read out when the excitation circuit 401 is disabled or disconnected from the soft magnetic component. Alternatively, the Hall elements H1, H2 can be read out when the excitation circuit 401 is active and a modulated signal is applied to the soft magnetic material, thereby modulating its magnetic sensitivity.

[0169] Figures 1 to 4 The figures illustrate several aspects or principles that can also be applied to other devices with soft magnetic components, and several of these aspects that can also be combined. Some examples will be described further.

[0170] Figure 5 A cross-sectional view of a semiconductor device 500 (e.g., a CMOS substrate) is shown, wherein a soft magnetic component 511 is electrically connected to the circuitry of the semiconductor substrate 500 via openings 516a, 516b through a polyimide layer 554, on top of which the soft magnetic component 511 is located. Figure 5In the example shown in FIG, each opening 516a, 516b accommodates an excitation contact E1, E2 and a sense contact S1, S2. The openings are substantially filled with soft magnetic material. This technology can be used to provide soft magnetic components with "back contacts" or "bottom contacts" not only for MI components but also for passive soft magnetic components (e.g., disc-shaped IMCs), or soft magnetic cores of integrated transformers, or soft magnetic cores of integrated fluxgates, for example to enable detection of mechanical problems (e.g., fractures or spalling).

[0171] Figure 5 The main purpose of FIG. 5 is to illustrate how the soft magnetic component 511 can be electrically connected to the circuitry of the semiconductor substrate by means of a “back contact”.

[0172] Will be in Figure 21 and Figure 22 Further described in the production of Figure 5 The method of the semiconductor substrate shown in FIG. Figure 5 As can be appreciated, the semiconductor substrate 500 can be based on a CMOS device having a passivation layer 552 and having contact pads 551. A buffer layer 554, such as a polyimide layer, is applied on top of the CMOS substrate; a first relatively large opening 516a is made in the buffer layer above the contact pads E1 and S1, and a second relatively large opening 516b is made in the buffer layer above the contact pads E2 and S2, and four relatively small openings are made to expose the contact pads 551. A conductive seed layer 555 can then be sputtered, and a soft magnetic material (e.g., FeNi or an FeNi alloy) can be applied on top of the seed layer, for example, by electroplating. It can be seen that the relatively large openings are thus mainly filled with soft magnetic material 511, and the soft magnetic component 511 thus formed has four "back contacts" or "bottom contacts".

[0173] Advantageously, the contact pad 551 is fabricated by a CMOS process (with high positional accuracy), and the positional tolerance of the openings 516 a , 516 b through the buffer layer 554 can be relaxed.

[0174] Figure 5 The semiconductor substrate does not show the circuit, but for example Figures 1 to 4 Any of the circuits shown in may be used, and other components (such as, for example, Hall plates or coils) may also be added, such as a planar coil beneath the soft magnetic component, or a coil wrapped around the soft magnetic component (e.g., using electrical tracks below and bonding wires above).

[0175] In a specific example, the soft magnetic component 511 is a disk, and the semiconductor substrate further includes a plurality of horizontal Hall elements arranged near the periphery of the disk, such as Figures 12 to 17B and Figure 19As shown in the figure.

[0176] In a variant (not shown), the sensor contact S1 coincides with the excitation contact E1 , and the sensor contact S2 coincides with the excitation contact E2 .

[0177] Figure 6 A semiconductor substrate 600 is shown, for example having an electronic circuit system ( Figure 6 Not shown in, but see e.g. Figures 1 to 4 and Figures 7 to 10 etc.), and a CMOS substrate having a soft magnetic component 611 of the circuit system electrically connected to the semiconductor substrate via a "side contact portion". Figure 6 The substrate 600 can be regarded as Figure 5 A variation of substrate 500 .

[0178] Will be in Figure 21 and Figure 23 Further described in the production of Figure 6 The method of the semiconductor substrate 600 shown in FIG. Figure 6 As can be appreciated, the semiconductor substrate 600 can be based on a CMOS device having a passivation layer 652 and having contact pads 651. A buffer layer 654, such as a polyimide layer, is applied on top of the CMOS device; a first relatively large opening 616a, 616b is made in the buffer layer 654 above the contact pads E1, S1, and a second relatively large opening is made in the buffer layer 654 above the contact pads E2, S2, and four relatively small openings are made to expose the contact pads 651. Then, a conductive seed layer 655 can be sputtered. Figure 5 Compared to the device of the present invention, the soft magnetic material has not yet been applied, but first a mask is applied to cover the area between the two relatively large openings 616a, 616b, and the opening is mainly filled with a conductive material (such as, for example, copper (Cu)). Then, the material in the middle area is removed, and a soft magnetic material (e.g., FeNi or FeNi alloy) is applied on top of the seed layer, for example, by electroplating. It can be seen that the relatively large opening is thereby mainly filled with non-magnetic material (e.g., Cu), and the soft magnetic component 611 thus formed can have two or more side contact surfaces 656a, 656b. In this way, in some embodiments of the present invention, the direction of the current flowing through the soft magnetic material can be better controlled, and the current can be made more uniform.

[0179] exist Figure 6 In a variant of this embodiment, the sensing contact S1 may coincide with the excitation contact E1 , and the sensing contact S2 may coincide with the excitation contact E2 .

[0180] In another or further variation, Figure 6The substrate includes a plurality of side contacts adjacent to the soft magnetic component 611, and these side contacts are electrically interconnected in the CMOS device below the soft magnetic component, and a copper region can be provided on top of each such side contact, and the copper region can then also be interconnected above the soft magnetic component (for example, using an RDL layer or using bonding wires). In this way, one or more coils can be formed around the soft magnetic component.

[0181] Figure 7 is a schematic representation of a semiconductor device 750 having a soft magnetic component 711, an excitation circuit 701 and a sensing circuit 702, and a processing circuit 706, the device being configured for detecting defects (e.g., fracture or (partial) peeling) of the soft magnetic component (e.g., in a diagnostic mode). The diagnostic function may be added to a semiconductor device having an active or passive soft magnetic component (e.g., may be added to a semiconductor device having an active or passive soft magnetic component). Figures 2 to 4 The soft magnetic component may be any of the following: an MR element, an MI element, an IMC, an integrated fluxgate, a core of an integrated transformer, etc.

[0182] Figure 17A and Figure 17B The middle figure shows a specific example of two integrated magnetic concentrators with Hall elements and such a “detection function”. Figure 18 The middle figure shows another specific example of an integrated fluxgate having such a “detection function”.

[0183] The excitation circuit can be configured to generate a DC signal or an AC signal. The processing circuit 706 can be configured to output a signal indicative of a defect. In a particular embodiment, the resistance or impedance of the soft magnetic component is compared to a predefined threshold, and if the resistance or impedance is greater than the threshold, an error is detected. Such fault detection may not be the only function of the semiconductor device. In fact, the semiconductor device can have multiple operating modes, can have additional circuit systems, and can have additional components, such as, for example, two or more Hall elements near the periphery of the soft magnetic component 711, or such as, for example, two or more coils arranged near or around the soft magnetic component 711. In Figure 7 In the example, the processing circuit may also output another signal or value, such as impedance, magnetic field value, current, torque, linear or angular position.

[0184] In a variant (not shown), the first sensing contact S1 may coincide with the first excitation contact E1 and the second sensing contact S2 may coincide with the second excitation contact E2.

[0185] The contacts can be implemented as "back contacts" and / or "side contacts", e.g. Figure 5 and / or Figure 6 As shown in the figure.

[0186] Figure 7 can be considered as Figure 1 and Figure 2 A variant or more detailed version of Figure 4 A subset of .

[0187] Figure 8 shows a semiconductor device 850, which can be viewed as Figure 7 The main difference is that the device 850 further includes one or more electromagnetic transducers T1, T2 (eg, Hall elements or coils) arranged adjacent to the soft magnetic component 811 and operatively connected to the soft magnetic component 811.

[0188] In a specific embodiment, the soft magnetic component 811 is an IMC, and the transducer is a horizontal Hall element arranged near the periphery of the IMC. In this case, the "excitation and readout circuit" 807 is typically referred to as a "bias and readout" circuit. Of course, the semiconductor substrate may include more than two horizontal Hall elements, as shown in FIG. Figure 15 、 Figure 16 、 Figure 19 、 Figure 20 As shown in the figure.

[0189] In another specific embodiment, the soft magnetic component 811 is an integrated fluxgate, and the transducers T1 and T2 are coils, such as spiral coils arranged near opposite ends of the soft magnetic component 811, or coils wrapped around the soft magnetic component. In this case, the "energizing and readout circuit" 807 can also be referred to as a "transmitter circuit" and a "receiver circuit." Of course, there can be more than two coils, for example, Figure 18 , where the first coil T1 may be referred to as the “excitation coil,” the second coil T2 may be referred to as the “pickup coil,” and the third (optional) coil T3 may be referred to as the “bias coil.”

[0190] The semiconductor device 850 can have two operating modes: for example, a first mode (e.g., diagnostic mode) for detecting defects of the soft magnetic component 811 mainly using circuits 801 and 802; and a second mode in which the soft magnetic component can be kept floating while signals are obtained from transducers T1, T2.

[0191] Figure 9 shows a semiconductor device 950, which can be viewed as Figure 8A variant of the semiconductor device 850, wherein the sensing contacts S1, S2 coincide with the excitation contacts E1, E2, respectively, and wherein the semiconductor device 950 further includes a modulator for modulating the magnetic permeability of the soft magnetic material (e.g., as part of the excitation circuit 901), and further includes a demodulator 917 (e.g., after the readout circuit 907, for demodulating signals obtained from the one or more electromagnetic transducers T1, T2).

[0192] The modulation may be AM modulation or FM modulation, or other suitable type of modulation.Preferably, "synchronous demodulation" is used. Figure 8 The sensing circuit 802 may be present (eg, for detecting defects in soft magnetic components), or may be omitted.

[0193] In a specific example, the soft magnetic component 911 may be an IMC, and the transducers T1 and T2 may be horizontal Hall elements. In another specific example, the soft magnetic component 911 may be an integrated fluxgate, and the transducers T1 and T2 may be coils.

[0194] Figure 10 shows a semiconductor device 1050, which can be viewed as Figure 8 Another variation of the semiconductor device 850, wherein the semiconductor device 1050 further includes a modulator for modulating the magnetic permeability of the soft magnetic component 1011 (e.g., as part of the excitation circuit 1001), and further includes a demodulator 1017 (e.g., after the sensing circuit 1002, for demodulating the signal obtained from the sensing circuit 1002). Figure 8 The one or more electromagnetic transducers T1, T2 and the "energizing and readout circuit" 807 may be present, or may be omitted.

[0195] The soft magnetic component 1011 can be a magnetoresistive (MR) component or a magnetic inductive (MI) component, for example, having an elongated shape. An optional horizontal Hall element can be positioned near the end of the soft magnetic component. The output signal provided by the processing circuit 1006 can be related to the magnetic field strength measured by the soft magnetic component 1011.

[0196] It should be noted that Figures 7 to 10 The processing circuitry in any of the may be implemented completely or partially in the analog domain and partially in the digital domain.The processing circuitry may include an analog-to-digital converter, a programmable processor, non-volatile memory, and the like.

[0197] Figure 11 (a) shows Figure 8 a top view of an example or variation of Figure 11 (b) shows Figure 8A side view of an example or variant of a 1111 magnetic induction (MI) element, wherein the sensing contacts S1, S2 coincide with the excitation contacts E1, E2, respectively, and wherein the soft magnetic component 1111 is a magnetic induction (MI) element having an elongated shape extending in a direction X parallel to the substrate, and wherein two horizontal Hall elements are positioned near the longitudinal ends of the MI element 1111. The processing circuit is not explicitly shown in FIG. Figure 11 (a) and Figure 11 (b), but see e.g. Figures 7 to 10 The semiconductor device 1150 may have various operating modes, such as one or more, two or more, or all three of the following:

[0198] i) a first operating mode, in which the soft magnetic component 1111 and the excitation circuit 1101 and the sensing circuit 1102 are used as an MI sensor for measuring a value indicative of electrical impedance and / or indicative of a magnetic field oriented in the X direction;

[0199] ii) a second operating mode, in which the soft magnetic component 1111 and a test circuit including the excitation circuit 1101 and the sensing circuit 1102, and optionally a comparator (not shown), are used to detect mechanical defects (e.g., cracks or peeling) of the soft magnetic component 1111;

[0200] iii) a third operating mode, in which the excitation circuit 1101 and the sensing circuit 1102 can be disabled, and in which the soft magnetic component 1111 is used as an IMC for guiding the magnetic flux lines, and in which the Hall elements H1, H2 are biased and read out to obtain two signals h1, h2, from which a magnetic field component Bx oriented in the X direction can be derived, for example using the formula Bx=(h2-h1), and / or a magnetic field component Bz oriented in the Z direction can be derived, for example using the formula Bz=(h1+h2).

[0201] exist Figure 11 (a) and Figure 11 In a variation of (b) (not explicitly shown), the semiconductor substrate 1100 further includes a modulator and a demodulator, for example, Figure 3 、 Figure 4 or Figure 10 Such semiconductor devices can provide:

[0202] iv) a fourth operating mode, wherein the magnetic permeability of the soft magnetic component 1111 is modulated and wherein the signal obtained from the sensing circuit 1102 is demodulated; and / or

[0203] v) A fifth operating mode, in which the magnetic permeability of the soft magnetic component 1111 is modulated and the signal obtained from the transducer (eg, Hall element) is demodulated.

[0204] Embodiments of the present invention may implement one or more or all of these five operating modes.

[0205] Figure 12 (a) shows a top view of a semiconductor device 1250, and Figure 12 (b) shows a side view of a semiconductor device 1250. The semiconductor device 1250 is Figure 11 (a) and Figure 11 (b) shows a variation of the semiconductor device 1150, wherein the soft magnetic component 1211 is an integrated magnetic field concentrator (IMC) having a disk shape, and wherein two horizontal Hall elements H1, H2 are positioned near the periphery of the IMC, spaced 180 degrees apart. The processing circuit is not explicitly shown in FIG. Figure 12 (a) and Figure 12 (b), but see e.g. Figures 7 to 10 The semiconductor device 1250 may have various operating modes, such as one or more of the following:

[0206] i) a first operating mode, wherein the soft magnetic component 1211 and a test circuit comprising the excitation circuit 1201 and the sensing circuit 1202, and optionally a comparator (not shown), can be used to detect defects (e.g., mechanical defects) of the IMC 1211, such as IMC breakage or peeling;

[0207] ii) a second operating mode, in which the test circuit can be disabled and the Hall elements H1, H2 can be biased and read out to obtain two signals h1, h2, from which the magnetic field component Bx oriented in the X direction can be derived, for example using the formula Bx = (h2-h1), and / or the magnetic field component Bz oriented in the Z direction can be derived, for example using the formula Bz = (h1+h2).

[0208] exist Figure 12 (a) and Figure 12 In a variation of (b) (not explicitly shown), the semiconductor substrate 1200 further includes a modulator and a demodulator, such as Figure 3 、 Figure 4 or Figure 9 Arranged as shown in the figure. Such equipment may have:

[0209] iii) A third operating mode, in which the magnetic permeability of the IMC 1211 is modulated and the signals h1 , h2 obtained from the Hall elements H1 , H2 are demodulated.

[0210] Figure 13 Yes Figure 12 (a) and Figure 12(b) or a variant thereof, a simplified representation of a semiconductor device 1250 having two electrical contacts c1, c2 and two horizontal Hall elements H1, H2, which are angularly spaced 180° apart. The Hall elements H1, H2 are positioned at a first radial distance from the center of the disk. The electrical contacts c1, c2 are positioned at a second radial distance from the center of the disk, the second radial distance being less than the first radial distance. Preferably, each contact c1, c2 is arranged in close proximity to a corresponding Hall element. Figure 13 In the example shown in FIG, the contact portions c1, c2 are arranged on a virtual line interconnecting two Hall elements, but the present invention is not limited thereto since this is not absolutely necessary for detecting defects.

[0211] Figure 14 Shown Figure 13 A variant in which the electrical contacts c1 , c2 are also positioned at a second radius smaller than the first radius, but the angular positions of the electrical contacts are angularly offset from the angular positions of the corresponding horizontal Hall elements by an angle θ.

[0212] Figure 15 Shown Figure 13 Another variation, wherein four horizontal Hall elements H1 to H4 are arranged near the periphery of the disk-shaped soft magnetic component and are angularly spaced apart by multiples of 90°, and wherein four electrical contacts c1 to c4 are arranged on a second radius smaller than the first radius, and wherein each electrical contact is arranged in close proximity to a corresponding Hall element.

[0213] In a diagnostic test for testing the mechanical integrity of an IMC, the contacts may be stimulated and sensed in pairs, for example by applying a voltage between c1 and c2 at a first moment, while c3 and c4 are kept floating (disconnected), and measuring a resulting first current, and comparing the first current to a predefined threshold; and by applying a voltage between c3 and c4 at a second moment, while c1 and c2 are kept floating (disconnected), and measuring a resulting second current, and comparing the second current to a predefined threshold; and if one or both of the first current and the second current are below the predefined threshold, a defect is detected.

[0214] But the invention is not limited to this particular solution, and other solutions are possible, such as by applying a voltage between c1 and c3 at a first moment and between c2 and c4 at a second moment, and comparing the resulting current with the predefined threshold.

[0215] exist Figures 13 to 16 In the embodiment shown in , the number of contacts is equal to the number of Hall elements, but this is not absolutely necessary, and in other embodiments the number of contacts may be higher or lower than the number of Hall elements as long as there are at least two contacts.

[0216] exist Figures 13 to 16 In the embodiment shown in , the contacts are all located at the same radial distance and are evenly angularly spaced, but that is not absolutely necessary for the invention to work.

[0217] Figure 16 Shown Figure 15 A variant in which the positions of the four electrical contacts c1 to c2 are angularly offset relative to the positions of the corresponding Hall elements, in this example by 45°, but other angular offsets may also be used.

[0218] Figure 17A A top view of an illustrative semiconductor substrate 1700 is shown, and Figure 17B A side view of an illustrative semiconductor substrate 1700 is shown having two soft magnetic components IMC1, IMC2 spaced apart by a distance dx, for example, in the range of about 1.0 mm to about 3.0 mm. In the example shown, each of the soft magnetic components has two electrical contacts, for a total of four contacts.

[0219] In one embodiment, the semiconductor substrate 1700 includes only a single test circuit including sensing and excitation circuits and optionally a comparator, and a plurality of switches for testing the mechanical integrity (or mechanical defect) of each of the IMCs individually.

[0220] In another embodiment, two IMCs are electrically connected in series, for example by providing an electrical interconnection between contact c2 of a first IMC and contact c3 of a second IMC in the semiconductor substrate, and by applying a test voltage across the entire chain (i.e., between c1 and c4), thereby generating a current through the entire chain, which can then be compared with a predefined threshold value. In fact, if one of the soft magnetic components breaks or peels off, the entire chain is broken, and an error is thus detected.

[0221] Figure 18 is a schematic representation of a semiconductor substrate 1800 including a passive soft magnetic component 1811 in the form of an integrated fluxgate. The semiconductor substrate includes at least two transducers T1, T2, T3 in the form of at least two coils wound around the soft magnetic component. As mentioned above, the third coil T3 is optional.

[0222] In addition to the actual function of the transducer (for sensing or measuring the magnetic field), in which the soft magnetic component 1811 is typically kept electrically floating, Figure 18The soft magnetic component further comprises two electrical contacts c1, c2, and the semiconductor substrate 1800 further comprises a test circuit for detecting defects of the soft magnetic component, the test circuit being similar to Figure 11 and Figure 12 The test circuit.

[0223] exist Figure 18 In the example shown in , the two contacts are schematically illustrated as two black circles, representing two “back contacts” or “bottom contacts”, but the present invention is not limited thereto, and “side contacts”, or a combination of “back contacts” and “side contacts” may also be used.

[0224] In another or further variation, the soft magnetic component comprises four electrical contacts, namely two excitation contacts and two sense contacts.

[0225] In another or further variation, one or both of the coils are planar spiral coils, preferably implemented in a semiconductor substrate, each coil being positioned with its center near an end of the elongated soft magnetic shape 1811 .

[0226] Figure 19 A semiconductor substrate 1900 having a soft magnetic structure is shown. The semiconductor substrate 1900 includes a central disk and twelve radially oriented segments, which are angularly spaced apart by multiples of 360° / 12=30°. The semiconductor substrate further includes twelve horizontal Hall elements H1, etc., which are arranged around the periphery of the central disk at angular positions corresponding to the angular positions of the radially oriented segments. Each of the twelve segments has two electrical contacts c1a, c1b, etc.

[0227] The center disk also has at least two electrical contacts, in this example: four electrical contacts c25 to c28. The semiconductor substrate 1900 may include: Figures 7 to 10 The electrical contacts of the various segments may be "daisy-chained," for example, with Figure 17B The "normal function" of this structure is "angle sensor". The electrical contacts and the test circuit for checking the mechanical integrity of the structure can be considered as additional functions, for example as diagnostic functions.

[0228] In a variant (not shown), the semiconductor substrate 1900 has only eight horizontal Hall elements and eight radially oriented segments that are angularly spaced apart by multiples of 45°.

[0229] Figure 20 A semiconductor structure 2000 is shown and may be viewed as Figure 19A variant in which the Hall elements H1 etc. are located near the inner ends of the radially oriented segments SR1 etc. It should be noted that the central disk is not absolutely necessary and may be omitted.

[0230] Figures 21 to 23 A flow chart is shown of a method that can be used to manufacture a semiconductor substrate (e.g., a CMOS substrate) having a soft magnetic component (e.g., comprising FeNi or an FeNi alloy) that is electrically connected to a circuit system of the semiconductor substrate by means of a "back contact" or "side contact," as described above. Figure 21 Can be considered as a general method. Figure 22 can be considered as Figure 21 A special case of wherein the electrical contact is a "back contact" or "bottom contact", e.g. Figure 5 As shown in the figure. Figure 23 can be considered as Figure 21 Another special case where the electrical contact is a "side contact", e.g. Figure 6 As shown in the figure.

[0231] Figure 21 A flow chart of a method 2130 for manufacturing a semiconductor substrate, or a semiconductor device (e.g., a sensor device) including such a semiconductor substrate is shown. The method 2130 includes the following steps:

[0232] a) In step 2131, a semiconductor substrate (e.g., a CMOS substrate) is provided, wherein the semiconductor substrate includes an electronic circuit system, wherein the electronic circuit system includes at least:

[0233] -Excitation circuit;

[0234] -processing circuits;

[0235] - Optionally, one or more of the following: sensing circuitry, at least one electromagnetic transducer (e.g., Hall element, coil), excitation and readout circuitry, modulator, demodulator;

[0236] b) In step 2132 , a buffer layer (eg, a polyimide layer) is optionally provided on top of the semiconductor substrate;

[0237] c) in step 2133, forming at least two openings through an upper layer (e.g., a protective layer or a buffer layer) of the semiconductor substrate to form a stimulus contact and / or a sense contact electrically connected to a circuit system of the semiconductor substrate;

[0238] d) in step 2134 , optionally providing at least one seed layer of a conductive material (eg, Cu) (eg, by sputtering);

[0239] e) In step 2135, a soft magnetic material (eg a thin film of ferromagnetic material such as FeNi or Fe-Ni alloy) is provided, for example on top of the seed layer (if present) by sputtering and / or electroplating.

[0240] Step d) may comprise providing at least one seed layer having a shape with at least one elongated portion.

[0241] Step d) may comprise providing two seed layers, for example comprising a first seed layer to ensure good adhesion (eg comprising Ti or a Ti alloy), and a second seed layer (eg Cu).

[0242] The method may further comprise the step f) of annealing the soft magnetic material while applying a static magnetic field oriented in a direction parallel to the semiconductor substrate.

[0243] The method may further comprise the step g) of passing a relatively strong current through the soft magnetic component during a relatively short period of time for creating the easy axis.

[0244] The method may further comprise one or more of the following steps:

[0245] cutting the semiconductor substrate to form a plurality of semiconductor dies;

[0246] mounting a semiconductor die on a lead frame;

[0247] The semiconductor die is encapsulated by applying a molding compound.

[0248] Figure 22 A flow chart of a method 2230 of manufacturing a semiconductor substrate, or a semiconductor device (eg, a sensor device) including such a semiconductor substrate is shown. Figure 22 The method can be considered as Figure 21 A special case of the method wherein the soft magnetic material is connected to the circuit system of the semiconductor substrate via a "back contact" or "bottom contact". The method 2230 includes the following steps:

[0249] a) In step 2231, a semiconductor substrate (e.g., a CMOS substrate) is provided, wherein the semiconductor substrate includes an electronic circuit system, wherein the electronic circuit system includes at least:

[0250] -Excitation circuit;

[0251] -processing circuits;

[0252] - Optionally, one or more of the following: sensing circuitry, at least one electromagnetic transducer (e.g., Hall element, coil), excitation and readout circuitry, modulator, demodulator;

[0253] c) in step 2233, forming at least two openings through an upper layer (e.g., a protective layer or a buffer layer) of the semiconductor substrate to form a stimulus contact and / or a sense contact electrically connected to the circuit system;

[0254] g) In step 2237, providing a "contact pad" that contacts the excitation contact and / or the sense contact;

[0255] b) in step 2232 , a buffer layer (e.g., a polyimide layer) is provided on top of the semiconductor substrate, and at least two (e.g., relatively large) openings are made through the buffer layer for contacting “contact pads”;

[0256] d) in step 2234, optionally providing at least one seed layer of a conductive material (e.g., Cu);

[0257] e) In step 2135, a soft magnetic material, eg a thin film of ferromagnetic material such as FeNi or a Fe-Ni alloy, is provided, eg on top of the seed layer (if present), eg by sputtering and / or by electroplating.

[0258] An advantage is that steps a), c) and g) can be performed using standard CMOS processes, using CMOS lithography.

[0259] and targeting Figure 21 The same comments made in respect of step d), step f) and the optional further steps also apply here.

[0260] It should be noted that steps 2233 and 2237 are typically used in CMOS processes to form bonding pads in the top metal of a "metal stack" (also called an "interconnect stack"). The bonding pads are then routed to the circuitry of the semiconductor substrate using the metal layers of the "metal stack."

[0261] Figure 23 A flow chart of a method 2330 of manufacturing a semiconductor substrate, or a semiconductor device (eg, a sensor device) including such a semiconductor substrate is shown. Figure 23 The method can be considered as Figure 21 A special case of the method wherein the soft magnetic material is connected to the circuit system of the semiconductor substrate via a "back contact" or "bottom contact". The method 2330 includes the following steps:

[0262] a) In step 2331, a semiconductor substrate (e.g., a CMOS substrate) is provided, wherein the semiconductor substrate includes an electronic circuit system, wherein the electronic circuit system includes at least:

[0263] -Excitation circuit;

[0264] -processing circuits;

[0265] - Optionally, one or more of the following: sensing circuitry, at least one electromagnetic transducer (e.g., Hall element, coil), excitation and readout circuitry, modulator, demodulator;

[0266] c) in step 2333, forming at least two openings through an upper layer (e.g., a protective layer or a buffer layer) of the semiconductor substrate to form a stimulus contact and / or a sense contact electrically connected to a circuit system of the semiconductor substrate;

[0267] g) In step 2337, providing a "contact pad" that contacts the excitation contact and / or the sense contact;

[0268] b) in step 2332 , a buffer layer (e.g., a polyimide layer) is provided on top of the semiconductor substrate, and at least two (e.g., relatively large) openings are made through the buffer layer for contacting “contact pads”;

[0269] d) in step 2334, optionally providing at least one seed layer of a conductive material (e.g., Cu);

[0270] h) in step 2338, providing a mask at the desired location of the soft magnetic component;

[0271] i) in step 2339 , depositing a conductive material (e.g., Cu) in the opening (e.g., by sputtering);

[0272] j) in step 2340 , providing a mask over the conductive material (e.g., Cu) present in the opening;

[0273] e) In step 2335, a soft magnetic material, eg a thin film of ferromagnetic material such as FeNi or a Fe-Ni alloy, is provided, eg on top of the seed layer (if present), eg by sputtering and / or by electroplating.

[0274] and targeting Figure 21 The same comments made in respect of step d), step f) and the optional further steps also apply here.

[0275] Reference numerals:

[0276] E1, E2 excitation contact

[0277] S1, S2 sensing contact parts

[0278] H1, H2 horizontal Hall elements

[0279] c1, c2 electrical contact parts

[0280] Reference numerals (module 100):

[0281] 00Semiconductor substrate

[0282] 01Excitation circuit

[0283] 02Sensing circuit

[0284] 04 buffer layer

[0285] 06Processing circuit

[0286] 07Bias and readout circuit for Hall element

[0287] 08Seed layer

[0288] 10Sensor structure or sensor arrangement

[0289] 11Soft magnetic components

[0290] 15 cavity

[0291] 16 openings

[0292] 17 Modulator

[0293] 30 methods

[0294] 50 semiconductor devices (e.g., sensor devices)

[0295] 51 contact pads

[0296] 52 passivation layer or intermediate layer

[0297] 53 passivation layer

[0298] 54 buffer layer (eg, polyimide layer)

[0299] 55 seed layer

[0300] 56 contact surface (on the side of the soft magnetic element)

Claims

1. A semiconductor device comprising: - a semiconductor substrate (100), the semiconductor substrate (100) comprising: an excitation circuit (101) for applying an excitation signal; and a soft magnetic component (111) for guiding magnetic flux lines; wherein the soft magnetic component (111) is electrically connected to the excitation circuit by means of at least two electrical contacts (E1, S1); The at least two electrical contact portions are back contact portions located at the bottom surface of the soft magnetic component (111), or side contact portions located at the side surface of the soft magnetic component (111); wherein the semiconductor substrate further comprises at least one electromagnetic transducer (H1, H2), the at least one electromagnetic transducer (H1, H2) being arranged adjacent to the soft magnetic component and being operatively connected to the soft magnetic component; Wherein, the excitation circuit comprises a modulator for providing a modulated signal to the soft magnetic component so as to modulate the magnetic permeability of the soft magnetic component; The semiconductor device further comprises a demodulator configured to demodulate a signal obtained from the at least one electromagnetic transducer (H1, H2).

2. A semiconductor device comprising: - a semiconductor substrate (100), comprising: an excitation circuit (101) for generating an excitation signal; a sensing circuit for measuring or detecting a response signal; and a soft magnetic component (111) for guiding magnetic flux lines; wherein the soft magnetic component (111) is electrically connected to the excitation circuit and to the sensing circuit by means of at least two electrical contacts (E1, S1); The at least two electrical contact portions are back contact portions located at the bottom surface of the soft magnetic component (111), or side contact portions located at the side surface of the soft magnetic component (111); The semiconductor device is configured to detect defects based on the response signal.

3. The semiconductor device according to claim 2, in, The semiconductor substrate further comprises at least one electromagnetic transducer (H1, H2), the at least one electromagnetic transducer (H1, H2) being arranged in close proximity to the soft magnetic component; and wherein the semiconductor substrate further comprises excitation and readout circuitry, the excitation and readout circuitry being connected to the at least one electromagnetic transducer; and wherein the semiconductor device has a first operating mode in which the excitation circuit and the sensing circuit are actively used to detect defects; And wherein the semiconductor device has a second mode of operation in which the excitation circuit is disabled and the energizing and readout circuit is used to obtain a signal from the electromagnetic transducer.

4. The semiconductor device according to claim 1 or claim 3, in, The at least one electromagnetic transducer is at least one Hall element; Or wherein the at least one electromagnetic transducer is at least one coil.

5. The semiconductor device according to claim 2, in, The excitation circuit (101) is electrically connected to the soft magnetic component (111) at a first excitation contact portion (E1) and a second excitation contact portion (E2); and The sensing circuit (102) is electrically connected to the soft magnetic component (111) at a first sensing contact portion (S1) and a second sensing contact portion (S2).

6. The semiconductor device according to claim 5, in, The first excitation contact portion (E1) overlaps with the first sensing contact portion (S1), and the second excitation contact portion (E2) overlaps with the second sensing contact portion (S2); Alternatively, the first sensing contact portion (S1) and the second sensing contact portion (S2) are located between the first excitation contact portion (E1) and the second excitation contact portion (E2).

7. The semiconductor device according to claim 1, in, The semiconductor substrate further includes a buffer layer; And wherein the soft magnetic component is arranged on top of the buffer layer.

8. The semiconductor device according to claim 7, in, The excitation circuit and the sensing circuit are electrically connected to the soft magnetic component by means of electrical interconnects through the buffer layer.

9. The semiconductor device according to claim 1, Further included is a biasing device for generating a DC magnetic field in the soft magnetic component.

10. The semiconductor device according to claim 1, in, The soft magnetic component has a cross-section with rounded or truncated edges or corners.

11. The semiconductor device according to claim 1, in, The semiconductor substrate further includes two soft magnetic trapezoidal shapes (512a, 512b) arranged near opposite ends (A, B) of the soft magnetic element (510).

12. The semiconductor device according to claim 1, in, The soft magnetic component has a circular shape; and wherein the semiconductor substrate includes a plurality of at least two horizontal Hall elements arranged near a periphery of the soft magnetic component; And wherein the soft magnetic component is electrically connected to the semiconductor substrate by means of a plurality of at least two electrical contacts (c1, c2).

13. The semiconductor device according to claim 1, further comprising a second soft magnetic component (IMC2); in, The first soft magnetic component (IMC1) comprises at least a first electrical contact portion (c1) and a second electrical contact portion (c2); and wherein the second soft magnetic component (IMC2) comprises at least a third electrical contact portion (c3) and a fourth electrical contact portion (c4); and wherein the second electrical contact portion (c2) is electrically connected to the third electrical contact portion (c3) in the semiconductor substrate; and The excitation signal is applied to the first electrical contact (c1), and the sensed signal is obtained from the fourth electrical contact (c4).

14. A method (2130) for producing a semiconductor substrate, comprising the steps of: a) providing (2131) a semiconductor substrate, said semiconductor substrate comprising an electronic circuit system, said electronic circuit system comprising at least an excitation circuit and a processing circuit; b) optionally providing (2132) a buffer layer on top of said semiconductor substrate; c) making (2133) at least two openings through the upper layer of the semiconductor substrate to form a stimulus contact and / or a sense contact electrically connected to the circuitry; d) optionally providing (2134) at least one seed layer of a conductive material; e) Providing (2135) a soft magnetic material, for example by sputtering and / or by electroplating.

15. The method (2230; 2330) of claim 14, further comprising one or more of the following features: -in, The semiconductor substrate provided in step a) is a CMOS substrate; - wherein the semiconductor substrate provided in step a) further comprises at least two horizontal Hall elements, and bias and readout circuits; - wherein the method further comprises: providing at least one seed layer of a conductive material; - wherein the semiconductor substrate provided in step a) further comprises a buffer layer on top of the semiconductor substrate; - further comprising the step of: performing wet etching or anisotropic etching after applying the soft magnetic material to provide rounded or truncated ends and / or edges; - wherein the method further comprises the step f): annealing the soft magnetic material when a static magnetic field oriented in a direction parallel to the semiconductor substrate is applied (2136); - wherein the method further comprises the step of creating an easy axis of magnetization by passing a relatively large current through the soft magnetic component during a predefined time.

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