Proceedings of the IConSSE FSM SWCU 2015, pp. SC.163–173 ISBN: 978-602-1047-21-7
SWUP
SC.163
Technology of anisotropic magneto resistive sensor on silicon substrate
Slamet Widodo and Tony Kristiantoro
Research Center for Electronic Telecommunications-LIPI Jl. Cisitu No.21154D, Komplex LIPI Sangkuriang,
Phone: +62-22-2504660, Fax: +62-22-2504659, Bandung-40135, Indonesia E-mail: slametwidodo50gmail.com; slametwi_dodoyahoo.co.id
Abstract
In this paper will be described magnetoresistive sensor design using thin film technology. A thin layer of alloy Ni-Cr will be grown on silicon substrates by
evaporation or DC-Sputtering. Also reported the results of the characterization of thin film coating deposition Ni
80
Cr
20
with and without magnetisation by SEM, EDS and GMR meter. By using photolithography and etching process, a layer of Ni-Cr alloy and then
patterned to form some of the microstructure of the inter-connected into a bridge. By applying a magnetic field in the arms of the bridge structures which face each other, will
create an asymmetry in the bridge. In this way, it is expected microstructure formed can serve as a magnetoresistive sensor that can detect magnetic fields below 5 mT, which
are needed in navigation systems.
Keywords AMR sensors, Nickel-chrome alloy Ni
80
Cr
20
, titanium Ti, AlAu
1. Introduction
Magnetoresistive effect is the change in resistivity of a material material due to the magnetic field, which was discovered by Thomson 1856, but only the last 30 years who have
a real interest and meaningful. Technology ferromagnetic thin film thickness 10-50 nm with the use of Anisotropic Magneto Resistive effect AMR to add to this technical improvement.
In addition, the effects of Giant Magneto Resistive GMR has been found, on the basis of thin ferromagnetic films clutch Baibich et al., 1988. The maximum resistivity changes up to
80 with the GMR effect, although with very high magnetic fields.
Sensor anisotropic magneto resistors AMR is a sensor which is generally suitable for the measurement of magnetic fields in the range up to 200μT. AMR sensors have high
sensitivity, wide operating temperature, the sensor offset is more stable than the Hall sensor and a wide operating frequency range close to 10 MHz.
AMR sensors with high sensitivity can be applied to regulate traffic, contactless measurement of electric current, measurement and movement in the engine rotation speed,
the Earths magnetic field sensor, electronic compass and navigation systems. Currently, AMR sensors have increased importance in the automotive industry with measurement
applications such as pedal position, wheel speed sensors for ABS anti-block system and the engine management system in which the sensor was used to measure the position of tenths
of a millimeter and the angle of the crankshaft to the ignition timing electronic. Details about the latest types of AMR sensors can be found in other works Dibbern, 1989 and on the
websites maintained by manufacturers such as Philips, Honeywell and others Fasching, 1994; Hauser Fulmek, 1992.
Technology of anisotropic magneto resistive sensor on silicon substrate
SWUP
SC.164
The need for sensors and transducers increased with many technological applications. Hrisoforou recently Hauser et al., 2000 reviewed the magnetic effects in the physical
sensors in the design and development at the International Workshop on Amorphous and nano structured Magnetic Materials Iasi - Romania 2001.
In the development of Micro Technology Integrated Circuits MTIC studied magnetoresistive sensor developed micro, which is used as a magnetic field sensor such as
the navigation system, servomotors, playback mechanism and other automated equipment. Solid state magnetic field sensors have advantages, such as the size and power compared to
the coil, and a superconducting flux gate Quantum Interference Detectors SQUID. As a physical phenomenon, this sensor is based on the anizotropic magnetoresistive effect of thin
ferromagnetic layer, the deposit on mono crystal silicon substrate Laimer Kolar, 2000; Fulmek Hauser, 1993.
Table 1. Comparison of magnetic sensors. Sensor type:
Min. B Max. B
Frequency range Induction coils
100 fT unlimited
0.1 mHz–1 MHz Hall sensors
10 nT 20 T
0–100 MHz Magnetoresistive Sensors
100 pT 100 mT
0–100 MHz Fluxgates
10 pT 1 mT
0–100 MHz SQUIDs
5 fT 1000 nT
0–100 kHz
2. AMR sensors theory
