Challenges for Integrated Magnetoresistive Sensors
Transcript of Challenges for Integrated Magnetoresistive Sensors
Challenges for integrated magnetoresistive sensors
P.P.Freitas, V. Martins, R.Ferreira, J.Gaspar, Elvira Paz, Jerome Borme ,Mariam Debs, Margaret Costa, Helder Rodrigues, Benito Rodriguez, Rumy Petrova, J.Piteira ( INL)
S.Cardoso, F.Cardoso, A.Rodrigues, Diana Leitao, R.Janeiro, J.P.Amaral, J.Germano, T.Costa, M.Piedade
(INESC MN)
E-mail: [email protected], [email protected]
Dublin , March 2012
Time (s)
fT to pT
pT
MCG
neuroelectronics
biochips
nT-µT
Magnetic Tunnel Junction sensorsBridge output
VOUT
Bottom Lead
Pinning Layer
Pinned LayerTunnel BarrierFree Layer
Top Lead
I
VBIAS
Linear range: tuneable : from 0.5mT to 100 mTMinimum field detectivity: nT Sensor size : few 100 nm2 to tens um2
Power comsumption: < 1mWTunable resistance: Ohm to 100’s kOhmsProcess compatibility: 200mm wafer process,
fully front end compatible
SPECS
-150 -100 -50 0 50 100 150
-600
-400
-200
0
200
400
600
Bridge Sensitivity : 26.7 mV/ mW /Oe
Bridge Sensitivity : 32.0 mV/ V /Oe
Bias Conditions :Voltage : 1000 mV Current : 0.300 mAPower : 0.3 mW
Bridge Output :Vmin : -532 mVVmax : +650 mVOutput Voltage : 1182 mV
Magnetic Response :Range (20-80%) : +29.40 OeHf : +2.39 [Oe]Hc : +4.15 [Oe]O
utpu
t Vol
tage
[mV]
External Magnetic Field [Oe]
Individual MTJ dimensions:5x70 m2
Magnetoresistive Sensors in AutomobilesApplications present in the Market
+ Navigation Systems + Electric Batteries Safety Systems+ Acceleration Sensors for Airbags (MEMS+Magnetoresistive)
Advantages:• Contactless, wear-free operating principle for angular and linear measurement• Large air gap• Large permissible air gap tolerances• Withstands extreme operating conditions• Full redundancy possible• Failsafe design• Flexible integration• High bandwidth for measurements in time slots of less than 100 ms
*Information from Sensitecwebsite
At least 15 different types of sensors using magnetoresistivedevices are already being integrated in automobiles!
2D Magnetometers/car navigation systemOutput from two orthogonal bridges
-314 -312 -310 -308 -306 -304 -302 -300 -298-320
-318
-316
-314
-312
-310
-308
-306
-304
Offset Corrected XX Field Sensor Output [mV]
Offs
er C
orre
cted
YY
Fie
ld S
enso
r Out
put [
mV]
YY F
ield
Sen
sor O
utpu
t [m
V]
XX Field Sensor Output [mV]
VBridge=5V-8 -6 -4 -2 0 2 4 6 8
-8
-6
-4
-2
0
2
4
6
8
XX Component Sensor
YY Component Sensor
Sensor output during a 360○ rotation
INESC FP7 ENIAC demonstrator , CMOS integration underway
DNA targets
DNA probes
Substrate
Passivation
Magnetic labels
Spintronic transducer
Hybridization of DNA probe and target
1-Scalable magnetoresistive biochips for point of carediagnostics
Trends in Biotechnology, August 2004
Labelled targets
Hybridize firstLabel after
CF chip, Snip to Chip
INESC-MN’s static, multiplexed MR biochip8 mm 40 µm
Sensor
Spotted probe
ftmolar sensitivity (DNA chip)multiplexed analysisCMOS, microfluidics, sensors
10-1610-1510-1410-1310-1210-1110-10 10-9 10-8 10-7 10-6 10-5
0.00
0.01
0.02
0.03
0.04
0.05
0.06
0.07
No target DNA
V b
indi
ng
ac /
V s
enso
r
ac
DNA concentration (M)
Passive hybridization Assisted hybridization
Non-Complementarytarget DNA*
Tech review, Lab On Chip 2012
Cell detectionKg1a cells
cell=5-10m
Cells marked with 50nmFeOx particles
Lab on Chip (2011)
INESC MN Dynamic immunoassay platform
Scanning probescurrent imaging in Ics
100 1000 10000 100000
10
100
Noi
se (n
T/H
z0.5 )
Frequency (Hz)
INESC MN-NEOCERA
2x2 m2
Other applications:-Non destruct.test. (in alt to(ultrasound and inductive)-nanoparticle imaging systemsSPIN, 2011
Time (s)
MCG (Magneto Cardiography) neasurements with hybrid SC +SV sensor (CEA-Dublin)
Noise level 3-4 pT at 10 Hz, at 4 K
Towards < pT/sqrt(Hz) detectivity at 1 Hz, at RT: medical imaginig
0 20 40 60 80 1000
50
100
150
VThermal+VShot = 0.42 nV/Hz0.5SRS SIM910 Amplifier,40 dBSpan 100Hz; RBW 1Hz; AVG 1000
51 pT @ 30 Hz97 pT @ 10 Hz
Wafer#1650 (Singulus), RxA 150 m2
PME2, Sensor# 55A[m2] = 676(26x26) ; RLow= 1.36 Ro = 2.1 ; TMR = 97%; S = 72 %/Oe
Sv[
pT/H
z0.5 ]
f[Hz]
RoomTemperature
ExternalLong Bias 35 Oe
IBias [A] 0.01 0.1
(1pT at 500 kHz, RT) Hybrid flux guide + TMR sensor
APL,2008
pT DC Magnetic Field DetectionHybrid SpinMEMS; DC to AC flux transformer
2006-2010, hybrid MR /thin film MEMS
1 nT at 1 Hz
2x6um2
SV sensordc flux
gate
ac flux
2012INESC MNINLUC Berkeley
Stimulation electrode
Recording electrode
Rat hippocampus
Synaptic current monitoring with highSpatial resolution ( with A.Sebastiao, IMM)
108200 108300 108400 108500 108600 108700 108800
-2,0x10-5
-1,0x10-5
0,0
1,0x10-5
2,0x10-5
3,0x10-5
4,0x10-5
Volta
ge (V
)Time (ms)
svon_Pump_Krebs_after1h30min_Oxigen__stimulation_30_100
MEMSMRCMOS
Remote sensor networks: RF antenna-MR sensor microsystem( large bandwidth)
APL, 2011
2mm antenna
SV