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13 pages, 4168 KiB

Open AccessArticle

Analysis of Orthogonal Coupling Structure Based on Double Three-Contact Vertical Hall Device

by Rongshan Wei and Yuxuan Du

Micromachines 2019, 10(9), 610; https://doi.org/10.3390/mi10090610 - 14 Sep 2019

Cited by 3 | Viewed by 2762

A vertical Hall device is an important component of 3D Hall sensors, used for detecting magnetic fields parallel to the sensor surface. The Hall devices described in existing research still have problems, such as large offset voltage and low sensitivity. Aiming to solve these problems, this study proposes a double three-contact vertical Hall device with low offset voltage, and a conformal mapping analysis method to improve the sensitivity of the device. Secondly, an orthogonal coupling structure composed of two sets of double three-contact vertical Hall devices is proposed, which further reduces the offset voltage of the device. Finally, the TCAD simulation software was used to analyze the performance of the devices, and an existing vertical Hall device was compared to ours. The results show that the orthogonal coupling structure in this study exhibits better performance, reaching an average voltage sensitivity of 17.5222 mV/VT and an average offset voltage of about 0.075 mV. In addition, the structure has the same magnitude of offset voltage in the four phases of the rotating current method. This characteristic enables the back-end circuit to more accurately filter out the offset voltage and acquire the Hall signal. Full article

(This article belongs to the Section A：Physics)

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5 pages, 319 KiB

Open AccessProceeding Paper

Low-Offset In-Plane Sensitive Hall Arrangement

by Siya Lozanova, Ivan Kolev, Avgust Ivanov and Chavdar Roumenin

Proceedings 2018, 2(13), 713; https://doi.org/10.3390/proceedings2130713 - 21 Dec 2018

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Abstract

A novel in-plane sensitive Hall arrangement consisting of two identical n-Si three-contact (3C) elements and realized in a common technological process, is presented. In the solution, the minimization of the offset and its temperature drift is achieved by cross-coupling of the outer device contacts. This terminals’ connection provides equalizing currents between the two substrates which strongly compensate the inevitable difference in the electrical conditions in the two parts of the arrangement. As a result, the residual offset of both integrated Hall elements at the output V_out(0) and its temperature drift are strongly minimized. The residual offset is about 160 times smaller than the single-configuration one. The obtained output voltage-to-residual offset ratio at sensitivity of S_RI ≈ 98 V/AT is very promising, reaching 6 × 10³ at temperature T = 40 °C and induction 1 T. As a result, increased metrological accuracy for numerous applications is achieved. For a first time through the novel arrangement a suppression of sensitivity in the presence of external magnetic field could be achieved in order to obtain permanent offset information. This is one of the key results in the Hall device investigation. Full article

(This article belongs to the Proceedings of EUROSENSORS 2018)

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4 pages, 313 KiB

Open AccessProceeding Paper

2D In-Plane Sensitive Hall-Effect Sensor

by Siya Lozanova, Ivan Kolev, Avgust Ivanov and Chavdar Roumenin

Proceedings 2018, 2(13), 711; https://doi.org/10.3390/proceedings2130711 - 30 Nov 2018

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Abstract

A new 2D (two-dimensional) in-plane sensitive Hall-effect sensor comprising two identical n-Si Greek-crosses is presented. Each of the crosses contains one central square contact and, symmetrically to each of their four sides, an outer contact is available. Outer electrode from one configuration is connected with the respective opposite contact from the other configuration, thus forming four parallel three-contact (3C) Hall elements. These original connections provide pairs of opposite supply currents in each of the cross-Hall structure. Also the obligatory load resistors in the outer contacts of 3С Hall elements are replaced by internal resistances of crosses themselves. The samples have been implemented by IC technology, using four masks. The magnetic field is parallel to the structures’ plane. The couples of opposite contacts of each Greek-cross are the outputs for the two orthogonal components of the magnetic vector at sensitivities S ≈ 115 V/AT whereas the cross-talk is very promising, reaching no more than 2.4%. The mean lowest detected magnetic induction B at a supply current I_s = 3 mA over the frequency range f ≤ 500 Hz at a signal to noise ratio equal to unity, is B_min ≈ 14 μT. Full article

(This article belongs to the Proceedings of EUROSENSORS 2018)

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14 pages, 23625 KiB

Open AccessArticle

A New Design of a Single-Device 3D Hall Sensor: Cross-Shaped 3D Hall Sensor

by Wei Tang, Fei Lyu, Dunhui Wang and Hongbing Pan

Sensors 2018, 18(4), 1065; https://doi.org/10.3390/s18041065 - 2 Apr 2018

Cited by 9 | Viewed by 6184

Abstract

In this paper, a new single-device three-dimensional (3D) Hall sensor called a cross-shaped 3D Hall device is designed based on the five-contact vertical Hall device. Some of the device parameters are based on 0.18 μm BCDlite^TM technology provided by GLOBALFOUNDRIES. Two-dimensional (2D) and 3D finite element models implemented in COMSOL are applied to understand the device behavior under a constant magnetic field. Besides this, the influence of the sensing contacts, active region’s depth, and P-type layers are taken into account by analyzing the distribution of the voltage along the top edge and the current density inside the devices. Due to the short-circuiting effect, the sensing contacts lead to degradation in sensitivities. The P-type layers and a deeper active region in turn are responsible for the improvement of sensitivities. To distinguish the P-type layer from the active region which plays the dominant role in reducing the short-circuiting effect, the current-related sensitivity of the top edge (S_top) is defined. It is found that the short-circuiting effect fades as the depth of the active region grows. Despite the P-type layers, the behavior changes a little. When the depth of the active region is 7 μm and the thickness of the P-type layers is 3 μm, the sensitivities in the x, y, and z directions can reach 91.70 V/AT, 92.36 V/AT, and 87.10 V/AT, respectively. Full article

(This article belongs to the Special Issue Magnetic Sensors)

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267 KiB

Open AccessProceeding Paper

A Novell Hall Magnetometer Using Dynamic Offset Cancellation

by Siya Lozanova, Svetoslav Noykov, L. Altunyan, A. Ivanov and Chavdar Roumenin

Proceedings 2017, 1(4), 329; https://doi.org/10.3390/proceedings1040329 - 9 Aug 2017

Cited by 1 | Viewed by 2287

Abstract

A novel Hall magnetometer using dynamic offset cancellation principle is presented. It consists from a single triangular silicon plate with three contacts and interface electronics. The proposed dynamic offset-cancelling measurement cycle includes three states. During each state, an external circuit is switched to the plate contacts in a certain way. This way, the direction of current flow through the Hall plate is changed from phase to phase. At the same time, the output voltage is measured. After averaging the obtained three voltages per a measurement cycle, the offset voltage cancelled and this way the offset-free Hall voltage is obtained. The obtained offset reduction factor is very promising, reaching 120–130. The Hall device sensitivity is about 25 V/AT. Full article

(This article belongs to the Proceedings of Proceedings of Eurosensors 2017, Paris, France, 3–6 September 2017)

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640 KiB

Open AccessProceeding Paper

Angle Measurement and 3D Magnetic Field Sensing Using Circular Hall Microsensor

by S. Lozanova, S. Noykov, A. Ivanov and C. Roumenin

Proceedings 2017, 1(4), 330; https://doi.org/10.3390/proceedings1040330 - 8 Aug 2017

Viewed by 1728

Abstract

A new three-axis magnetometer for both 3-D magnetic field sensing and contactless in-plane 360° absolute angle encoding has been developed. The magnetometer is based on the Hall effect and consists of a circular in-plane sensitive CMOS Hall-effect microsensor, biasing and signal conditioning circuits. The sensing device contains a narrow n-well ring with a chain of contacts positioned radial on the ring. The signal conditioning circuit gives two output analogue signals: a voltage V_z, proportional to the magnetic field component B_z, and a sine wave function V_xy(t). The magnitude of the in-plane magnetic field B(x,y) is directly proportional to the sine amplitude and the phase Ψ corresponds to the angle between the applied in-plane magnetic field and a reference direction. Full article

(This article belongs to the Proceedings of Proceedings of Eurosensors 2017, Paris, France, 3–6 September 2017)

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