Operating principles of bipolar transistor magnetic sensors

The sensitivity of bipolar magnetotransistor with the base in the well has been studied. An experiment is conducted to compare the performance of two designs of dual-collector lateral bipolar magnetotransistor, which are formed in a uniformly doped substrate or a diffused well. Their respective differential collector voltages are found to differ in sign under an applied magnetic field. It is noted that acquiring an adequate understanding of the mechanism underlying the operation of the device should help one improve its magnetic-field sensitivity. A low velocity of surface recombination and an extraction of the injected electrons by a base-well р-n junction determined operating mode with a deviation of two flows of charge carriers.

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“…Consider the planar magnetotransistor studied by Vinal and Masnari [9]. It has two base contacts and two collector contacts arranged as in Fig.…”

Section: Magnetotransistor With Variable Sensitivitymentioning

confidence: 99%

The three-collector Magnetotransistor: Variable sensitivity

Amelichev

Tikhonov

Cheremisinov

2013

2013 IEEE XXXIII International Scientific Conference Electronics and Nanotechnology (ELNANO)

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“…In the lateral BMT in CMOS technology [10] the base is the diffusion well. In the lateral BMT with suppressed sidewall injection between the emitter and the collector, the base-well is doped or oxide ring, which limits the flow of injected charge carriers along the surface and reduces the influence of surface recombination [11][12][13].…”

Section: Introductionmentioning

confidence: 99%

Dual-Collector Lateral Bipolar Magnetotransistor: Negative Sensitivity and Galvanomagnetic Effects

Tikhonov¹

2008

TOEEJ

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The results of measurement of the dual-collector lateral bipolar magnetotransistor, generated in a uniformly doped substrate or in a diffused well were compared and it was established that the collector voltage difference under the influence of a magnetic field has a different sign. The effect is interpreted using the concept of the magnetic sensitivity sign. By means of device-technological simulation we investigated the distribution of charge carriers, current density and recombination speed in a magnetotransistor generated in a well with external connection of substrate and well contacts. It is shown that at a planar arrangement of substrate contacts is responsible for the volumetric concentration-recombination mechanism of negative relative magnetic sensitivity due to Galvanomagnetic effects.

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“…In general, a magnetic device is a functional connection between an MR (Hall device) and an MT; that is, a magnetic device is a superposition of Hall action and nonequilibrium majority carriers [9]- [12]. Notably, the magnetic influence of the MT is detected at the collector contact as a nonlinear output, rather than at the Hall contact in the MR as a linear output.…”

Section: Introductionmentioning

confidence: 99%

Interaction Between Magnetoresistor and Magnetotransistor in the Longitudinal and Folded Vertical Hall Devices

Sung

2004

IEEE Sensors J.

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This study investigates the one-dimensional longitudinal and folded vertical Hall devices, fabricated in a standard 0.35-m CMOS process. The smallest nonlinearity error 0.18%, the minimum offset 0.29 mV, and the maximum supply-current-related sensitivity RI = 3 837 V A T, are obtained with a 10-mA bias current excited by the supply voltage of 0.6 V. The main magnetic mechanism is that the filament current of the vertical magnetoresistor is directly injected into the base region of the bulk magnetotransistor (BMT) to increase the density of minority carriers and then enhance the magnetosensitivity. Furthermore, the induced Hall voltage of the longitudinal vertical Hall device is proportional to the bias current, but the folded vertical Hall device is inversely impacted. This advantage makes it possible to get a low-power folded vertical Hall device. The folded style not only reduces the nonlinearity error but also minimizes the offset. Unfortunately, the tradeoff is a fall in sensitivity. The BMT is applied to increase magnetic sensitivity and to compensate for this negative impact. Index Terms-Folded vertical Hall device, Hall effect, magnetoresistor (MR), magnetosensor, magnetotransistor (MT).

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Operating principles of bipolar transistor magnetic sensors

Cited by 30 publications

References 5 publications

The three-collector Magnetotransistor: Variable sensitivity

The three-collector Magnetotransistor: Variable sensitivity

Dual-Collector Lateral Bipolar Magnetotransistor: Negative Sensitivity and Galvanomagnetic Effects

Interaction Between Magnetoresistor and Magnetotransistor in the Longitudinal and Folded Vertical Hall Devices

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