Double Hall sensor structure reducing voltage offset

Abstract

In this paper, we report on the double Hall sensor structure (DHSS) in which the voltage offset can be effectively reduced. The DHSS is composed of two standard Hall sensors that are activated with two currents from electrically independent current sources. The operation principle of the DHSS is explained in detail, and the concluded properties of the DHSS are confirmed in the experimental part of the paper. The measurements are performed on DHSSs based on InSb thin films. The offset is reduced by about three orders of magnitude. The minimum value of the reduced offset obtained is 10 μV. It appears that the minimum reduced offset is limited by the electric noise. The advantage of DHSS is that it can be manufactured with the standard thin film technology enabling effective miniaturization of the system. The DHSS can effectively be used for the measurements of the Hall effect in ultra-thin layers containing the two dimensional electron gas, such as the epitaxial graphene.

The X-Hall Sensor: Toward Integrated Broadband Current Sensing

“…In contrast to spun Hall sensor and due to the specific geometrical shape, the contacts of the X-Hall probe are dedicated to a single purpose (either biasing or sensing), so they can be optimized according to their specific function. The bias contacts are large-sized to minimize the access resistance and are orthogonally oriented to the edges of the probe to maximize the sensitivity [21]. The sensing contacts are small-sized to minimize the parasitic capacitance associated with the contacts and to maximize the sensitivity [21].…”

“…The bias contacts are large-sized to minimize the access resistance and are orthogonally oriented to the edges of the probe to maximize the sensitivity [21]. The sensing contacts are small-sized to minimize the parasitic capacitance associated with the contacts and to maximize the sensitivity [21]. However, sensing contacts cannot be shrunk too much, otherwise, lithography errors on the exact position of the contacts will increase the offset in the probe [21].…”

“…The sensing contacts are small-sized to minimize the parasitic capacitance associated with the contacts and to maximize the sensitivity [21]. However, sensing contacts cannot be shrunk too much, otherwise, lithography errors on the exact position of the contacts will increase the offset in the probe [21].…”

“…This paper presents and experimentally investigates the X-Hall sensor architecture as a solution for broadening the bandwidth of purely Hall-effect sensors by both eliminating the spinning-current technique (thus, the associated methodological limit) and minimizing the capacitive load seen by the Hall probe. The X-Hall sensor is based on an innovative topology of the Hall probe: the classic spinning-current technique is replaced by a purely DC biasing, and a passive offset reduction is implemented at the probe level, in contrast to [21] where it is carried out at the sensor level. From a general standpoint, the passive offset compensation defined in the X-Hall architecture preserves an adequate offset reduction performance and offers the paramount advantage of not limiting the bandwidth, though it is less efficient than the spinningcurrent technique operated at low spinning frequency.…”

Experimental Assessment of a Broadband Current Sensor based on the X-Hall Architecture

“…Minimization of the capacitive load is facilitated by the removal of all the switches required by the spinning-current technique. At the same time, the X-Hall sensor lowers the high intrinsic offset of the Hall probe by using passive offset compensation at the probe level, in contrast to [6] where it is implemented at the sensor level. According to [5] and [7], replacing the spinning-current biasing with a purely DC-biasing allows the Hall sensor to theoretically achieve a bandwidth of tens to hundreds of MHz.…”