Compensation of the Piezo-Hall Effect in Integrated Hall Sensors on (100)-Si

Ausserlechner, Udo; Motz, Mario; Holliber, Michael

doi:10.1109/jsen.2007.907039

Cited by 33 publications

(25 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In (22) the signals h 13 and h 24 are lengthy functions of rotation angle, assembly tolerances, and magnet according to (4) and (18). The expressions get shorter if we approximate them by a Taylor series like in [1,4,5], which is admissible for small assembly tolerances.…”

Section: Errors Of Axialc4 Sensors Due To Assembly Tolerancesmentioning

confidence: 99%

See 1 more Smart Citation

A Theory of Magnetic Angle Sensors With Hall Plates and Without Fluxguides

Ausserlechner¹

2013

PIER B

Self Cite

View full text Add to dashboard Cite

Abstract-Magnetic angle sensors detect the angular position of a permanent magnet attached to a rotating shaft. The magnet is polarized diametrically to the rotation axis. No soft magnetic flux guides are present. The semiconductor die is placed on and orthogonal to the rotation axis. There are two kinds of systems: (i) perpendicular systems detect the field components perpendicular to the rotation axis, and (ii) axial systems detect the component parallel to the rotation axis. The former use magneto-resistive sensors or vertical Hall effect devices; the latter use Hall plates. This paper focuses on axial systems, derives their conceptual limitations, and compares them with perpendicular systems. An optimized system and optimum shapes of magnets are reported. Angle errors due to assembly tolerances of magnet and sensor versus shaft are explained. It is proven that assembly tolerances of optimized axial systems give three times larger errors than perpendicular systems.

show abstract

Section: Errors Of Axialc4 Sensors Due To Assembly Tolerancesmentioning

confidence: 99%

“…As sensor elements one can use horizontal Hall plates (HHall) [9,10] or MAGFETs [11]. The main advantage is the mature technology of HHalls, where the problems of offset [12] and mechanical stress [13,14] are solved. Another advantage is the differential sensing principle, which is robust against background magnetic fields.…”

Section: Introductionmentioning

confidence: 99%

A Theory of Magnetic Angle Sensors With Hall Plates and Without Fluxguides

Ausserlechner¹

2013

PIER B

Self Cite

View full text Add to dashboard Cite

show abstract

“…On the other hand, a comparison of magnetic sensitivities of two such Hall plates, one with large contacts along the -axis and the other one with large contacts along the -axis, could be used to determine the piezoresistive coefficient 44 without measuring resistances. If one uses an isotropic biaxial stress state = (e.g., in a wafer bow experiment [53]) to characterize the piezo-Hall effect, the current related magnetic sensitivity does not depend on the piezoresistance effect. In smart silicon Hall sensors with mechanical stress compensation the piezoresistance effect leads to a − dependence of the magnetic sensitivity, whereas the piezoHall effect has a + dependence: this leads to increased complexity of the compensation circuit as described in chapter 16.6.3 in [22].…”

Section: Optimization Of Stress Sensor Devicesmentioning

confidence: 99%

An Analytical Theory of Piezoresistive Effects in Hall Plates with Large Contacts

Ausserlechner

2018

Advances in Condensed Matter Physics

Self Cite

View full text Add to dashboard Cite

Four-terminal transducers can be used to measure the magnetic field via the Hall effect or the mechanical stress via the piezoresistance effect. Both effects are described by an anisotropic conductivity tensor with small offdiagonal elements. This has led other authors to the conclusion that there is some kind of analogy. In both cases the output voltage depends on the geometry of the device and the size of the contacts. For Hall plates this influence is accounted for by the Hall-geometry factor. The alleged analogy proposes that the Hall-geometry factor also applies to four-terminal stress transducers. This paper shows that the analogy holds only for a limited class of devices. Moreover, it is shown that devices of different geometries may have identical magnetic field sensitivity but different mechanical stress sensitivities. Thus, shape optimization makes sense for mechanical stress sensors. In extreme cases the output voltages of vertical Hall-effect devices may have notable magnetic field sensitivity but zero mechanical stress sensitivity. As byproduct, exact analytical formulae for the equivalent resistor circuit of rectangular and circular devices with two perpendicular mirror symmetries are given. They allow for an accurate description of how mechanical stress and deformation affect the output offset voltage and the magnetic sensitivity of Hall-effect devices.

show abstract

“…However, for the majority of Hall sensor applications these effects are parasitic. For planar Hall plates in (100)-silicon [7] the relative sensitivity change is S H S H = P 12 σ x x + σ yy + P 11 σ zz (1) where P 12 and P 11 denote the piezo-Hall coefficients with respect to in-plane and out-of-plane normal stresses and σ x x , σ yy , σ zz denote the normal stresses. The piezo-Hall coefficient P 12 is the relative sensitivity of the Hall plate to σ x x + σ yy .…”

mentioning

confidence: 99%

“…Variations of the temperature cause a change of magnetic sensitivity via the temperature dependent mobility and Hall scattering factor [8]. Moreover, a change of the environmental conditions of packaged Hall sensors, i.e., temperature, humidity [9], [10], and cyclic loads [11] lead to a change of the package stress and consequently lead to a change of the sensitivity [5], [12]. An optimized assembly process can help to decrease the stress-related sensitivity drift of Hall sensors [13], [14].…”

mentioning

confidence: 99%

Package Stress Monitor to Compensate for the Piezo-Hall Effect in CMOS Hall Sensors

Huber¹,

Schott²,

Oliver

2013

IEEE Sensors J.

View full text Add to dashboard Cite

Package-induced stress changes the sensitivity of planar Hall plates via the piezo-Hall effect. In this paper, we present a novel stress sensor that allows us to compensate for this undesired mechanical cross-sensitivity. The new CMOScompatible sensor is based on a Wheatstone bridge built of eight appropriately arranged n-and p-doped piezoresistors. The differential output signal V bridge of the sensor is proportional to the sum of in-plane normal stresses σ x x +σ yy with the sensitivity S bridge,σ = ∂ V bridge / V bias /∂ σ x x + σ yy = −0.047GPa −1 . Doping concentrations larger than 10 19 cm −3 for both the n-and p-type resistors are used to minimize the parasitic resistor mismatch due to the junction field effect. Simultaneously, the highly doped resistors keep the relative thermal cross-sensitivity of the sensor as small as 74 ppm K −1 . In contrast to conventional sensor rosettes, the new sensor has the advantage of offering a differential output signal. The measured signal is successfully used to decrease the stress-impact on the sensitivity of CMOS Hall sensors by a factor of five.

show abstract

Compensation of the Piezo-Hall Effect in Integrated Hall Sensors on (100)-Si

Cited by 33 publications

References 12 publications

A Theory of Magnetic Angle Sensors With Hall Plates and Without Fluxguides

A Theory of Magnetic Angle Sensors With Hall Plates and Without Fluxguides

An Analytical Theory of Piezoresistive Effects in Hall Plates with Large Contacts

Package Stress Monitor to Compensate for the Piezo-Hall Effect in CMOS Hall Sensors

Contact Info

Product

Resources

About