SAW Device/Sensor Modeling for SPICE Simulation : MOS - AK

53 Pages·2012·1.72 MB·English

SAWDevice/SensorModelingforSPICESimulation:MOS-AK/GSAINDIA2012
(cid:13)cProf.A.B.Bhattacharyya
SAW Device/Sensor Modeling for SPICE
Simulation : MOS - AK / GSA INDIA 2012
A.B.Bhattacharyya
Emeritus Professor
(Email : [e-mail])
JIIT, Noida
Association : Suneet Tuli, IIT Delhi
Assistance :
Indranil Sen, Shishir Jain
JIIT,Noida
March 17, 2012
SAWDevice/SensorModelingforSPICESimulation:MOS-AK/GSAINDIA2012
(cid:13)cProf.A.B.Bhattacharyya
Programs at JIIT
PASSIVE COMPONENT COMPACT MODELING
Physical Modeling of Inductor - Inductor as an interconnect
SPICE Modeling of MEMS Micromechanical Structures -
Cantilevers, Membranes
SAW Sensor Modeling
High Temperature MOS Modeling
SAWDevice/SensorModelingforSPICESimulation:MOS-AK/GSAINDIA2012
(cid:13)cProf.A.B.Bhattacharyya
Agenda
SAW Basics
Motivation
Primitive Structures
Benchmark Circuits
Benchmark Tests
Motivation For SAW SPICE Modeling
Mason Equivalent Circuit
SPICE Modeling
Capacitance Modeling
Simulation
Validation
Model Integration to SPICE Simulator in Verilog-A
Conclusion
References
SAWDevice/SensorModelingforSPICESimulation:MOS-AK/GSAINDIA2012
(cid:13)cProf.A.B.Bhattacharyya
SAW Basics
Compression
Dilation
u ,u
y z
uy Monochromatictravelingacousticwavein
z-directioncanbedescribedby:
•particledisplacementvectoru(z,t),
•quasistaticelectricpotentialφ(z,t)
s z
t
n
e
m
y
e
c
a
pl uz
s
di
e
cl 1 3
ti
r
a
P
Depth (wavelengths)
SAWDevice/SensorModelingforSPICESimulation:MOS-AK/GSAINDIA2012
(cid:13)cProf.A.B.Bhattacharyya
SAW Basics
Surface Acoustic Wave(Rayleigh Wave) excitation on the
surface of a piezoelectric substrate through interdigital
transducer was realized by R.M. White , at the University of
[3]
California, Berkeley in early 70’s by R.M. White.
The alternating electric field applied between finger pairs of
IDT periodic strain field in the piezo-substrate to standing
acoustic wave ⇒ Propagating bidirectional wave in the
medium.
The elastic wave generated ⇒ composition of compressional
and shear waves in a fixed ratio.
Typical mechanical wave velocity 3× 105 cm/sec. ⇒ Five
order smaller than EM Wave Velocity ⇒ Miniaturization of
electronic components.
SAW IDT structures are realized by standard micro
lithographic technique.
SAWDevice/SensorModelingforSPICESimulation:MOS-AK/GSAINDIA2012
(cid:13)cProf.A.B.Bhattacharyya
SAW Basics
The Wave Energy is confined within wavelength
distance/depth of the substrate ⇒ acts as a wave guide.
Surface confinement of wave energy makes it extremes
sensitive to surface perturbation ⇒ sensor application.
Surface Potential of Wave / Applied voltage to IDT =
Transfer Function =φ± = µ V , where µ = substrate
s 1 s
dependent (Freq. Independent)
φ+(z) = µ (cid:80)n−1V exp jk(z-z ), z : position of nth fingers
s n=0 n n n
pair.
SAWDevice/SensorModelingforSPICESimulation:MOS-AK/GSAINDIA2012
(cid:13)cProf.A.B.Bhattacharyya
Motivation
Surface Acoustic Waves are sensitive to
Ambient Temperature
Forces
Acceleration
Electric Field Strength
Dew Point
Gas concentration
Gas Flow
Pathogens,E-coli, virus, bacteria, DNA
Gas trace in environment(e-nose)
Automobile emission
A wide range of sensors
In Communication:
Delay Line, Band pass filters, Dispersive filters, Resonators,
Convolvers, Correlators, RF ID...
SAWDevice/SensorModelingforSPICESimulation:MOS-AK/GSAINDIA2012
(cid:13)cProf.A.B.Bhattacharyya
Primitive IDT Structures - I
Finger
Width Finger
Spacing
Period(p)
p/2
Aperture
Voltage source
SAWDevice/SensorModelingforSPICESimulation:MOS-AK/GSAINDIA2012
(cid:13)cProf.A.B.Bhattacharyya
Primitive IDT Structure - II Delay Line
Transmitter Receiver
V I
1 2
φ+
A φ+
B
V I
1 2
Piezoelectric
Substrate
SAWDevice/SensorModelingforSPICESimulation:MOS-AK/GSAINDIA2012
(cid:13)cProf.A.B.Bhattacharyya
Double-Electrode IDT Structure =⇒ Cancellation of
Reflection from Metal Electrodes
Transmitter Receiver
λ
8
V I
1 2
0
π
λ
8
V I
1 2
Piezoelectric
Substrate
∆z = R · K2 +R · h +(cid:0)h(cid:1)2 [For h << 0.2%]
z0 P 2 m λ λ λ
∆ν ≈ K2
ν 2 Energystorage
Mechanicalloading