1 Introduction
The magnetoresistance (MR) effect is
the change of material resistance caused by an applied
magnetic field, which has been extensively applied in sen-
sors [1], magnetic memories [2], and logic devices [3].
Systems based on MR have high potential of applications
in some modern technologies such as frequency synthesiz-
ers [4] and microwave detectors [5]. In recent years, MR in
non-magnetic materials has been attracting more attention.
In contrast to magnetic materials, non-magnetic materials
exhibit larger MRs [6, 7] and the resistivity shows an ap-
proximately linearly increase with the external magnetic
field.
Among these non-magnetic materials, silicon (Si) at-
tracts more attention [8–17] because of its great compati-
bility with the current CMOS technology and low cost [14].
Large MR ratios of over 10,000% can be realized in Si at a
low temperature of 4 K [15]. A 1000% MR ratio in Si has
been observed at an applied voltage of more than 70 V [16].
A room-temperature MR ratio of 180% can already be
achieved for Si in a strong magnetic field of 40 T at a bias
voltage of 1.0 V [17]. However, reports of remarkable
room-temperature MRs in Si at a moderate operation con-
dition, i.e., low applied voltage and relatively weak mag-
netic field, are still lacking.
In this paper, we investigate the room-temperature MR
effect of Si strip devices, which are already employed for
particle detection in high-energy physics collision experi-
ments [18]. A room-temperature MR ratio of
∼
400% is re-
alized at the applied voltage of 1.0 V and magnetic field of
0.8 T using a one-top-contact measuring configuration.
Moreover, MR saturation is observed with this measuring
configuration for a given applied voltage as the magnetic
field increases. However, no MR saturation is observed in
the ten-top-contact measurement and the MR ratio is only
∼
155% even at the magnetic field of 1.2 T and applied
voltage of 1.0 V.
2 Experiments
The Si strip devices are fabricated on
300
μ
m thick n-type Si wafers. In this study, lightly doped
Si wafers with a carrier density of 1.0
×
10
12
cm
–3
are em-
In this paper, we report remarkable room-temperature magne-
toresistance (MR) in silicon strip devices. Saturating and non-
saturating MRs can be realized based on the measuring con-
figurations with one top contact and ten top contacts, respec-
tively. Using the one-top-contact measurement, a saturating
MR ratio of
∼
400% is obtained at an applied voltage of only
1.0 V when the magnetic field is larger than 0.8 T. While the
non-saturating MR is achieved in the ten-top-contact meas-
urement and the MR ratio is only
∼
155% for the 1.0 V ap-
plied voltage even under the magnetic field of 1.2 T. The dif-
ferences for MR ratio values and change trends in these two
measuring configurations are attributed to the enhanced Hall
electric field with the increase of the top contact number.
2
H. Guo et al.: Remarkable RT magnetoresistance in silicon strip devices
© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Do'stlaringiz bilan baham: |