Show simple item record

dc.contributor.advisorKosel, Jürgen
dc.contributor.authorSun, Jian
dc.date.accessioned2013-09-01T06:37:34Z
dc.date.available2013-09-01T06:37:34Z
dc.date.issued2013-06-27
dc.identifier.doi10.25781/KAUST-KM2JN
dc.identifier.urihttp://hdl.handle.net/10754/300641
dc.description.abstractIn this dissertation, the extraordinary magnetoresistance (EMR) effect in semiconductor/metal hybrid structures is studied to improve the performance in sensing applications. Using two-dimensional finite element simulations, the geometric dependence of the output sensitivity, which is a more relevant parameter for EMR sensors than the magnetoresistance (MR), is studied. The results show that the optimal geometry in this case is different from the geometry reported before, where the MR ratio was optimized. A device consisting of a semiconductor bar with length/width ratio of 5~10 and having only 2 contacts is found to exhibit the highest sensitivity. A newly developed three-dimensional finite element model is employed to investigate parameters that have been neglected with the two dimensional simulations utilized so far, i.e., thickness of metal shunt and arbitrary semiconductor/metal interface. The simulations show the influence of those parameters on the sensitivity is up to 10 %. The model also enables exploring the EMR effect in planar magnetic fields. In case of a bar device, the sensitivity to planar fields is about 15 % to 20 % of the one to perpendicular fields. 5 A “top-contacted” structure is proposed to reduce the complexity of fabrication, where neither patterning of the semiconductor nor precise alignment is required. A comparison of the new structure with a conventionally fabricated device shows that a similar magnetic field resolution of 24 nT/√Hz is obtained. A new 3-contact device is developed improving the poor low-field sensitivity observed in conventional EMR devices, resulting from its parabolic magnetoresistance response. The 3-contact device provides a considerable boost of the low field response by combining the Hall effect with the EMR effect, resulting in an increase of the output sensitivity by 5 times at 0.01 T compared to a 2-contact device. The results of this dissertation provide new insights into the optimization of EMR devices for sensor applications. Two novel concepts are presented, which are promising for realizing EMR devices with high spatial resolution and for opening new applications for EMR sensors in the low-field regime.
dc.language.isoen
dc.subjectmagneto resistance
dc.subjectextraordinary magneto resistance
dc.subjectmagnetic sensors
dc.subjectIII-V Semiconductor
dc.titleExtraordinary Magnetoresistance Effect in Semiconductor/Metal Hybrid Structure
dc.typeDissertation
dc.contributor.departmentComputer, Electrical and Mathematical Sciences and Engineering (CEMSE) Division
thesis.degree.grantorKing Abdullah University of Science and Technology
dc.contributor.committeememberFoulds, Ian G.
dc.contributor.committeememberGrundler, Dirk
dc.contributor.committeememberHadwiger, Markus
thesis.degree.disciplineElectrical Engineering
thesis.degree.nameDoctor of Philosophy
refterms.dateFOA2018-06-14T06:36:09Z


Files in this item

Thumbnail
Name:
Jin Sun Dissertation.pdf
Size:
5.409Mb
Format:
PDF
Description:
Dissertation

This item appears in the following Collection(s)

Show simple item record