pulse measurement for thermal impedance characterization
TRANSCRIPT
Pulse Measurement for Thermal Impedance Characterization: HiCuM Simulation with
Recursive Electro-thermal Network
A.K. Sahoo, S. Fregonese, N. Malbert, T. Zimmer
HiCuM Workshop 2011
28 June 2011 2/21HiCuM Workshop 2011
The down scaling of electronic device dimensions is the main way to achieve better high frequency performance.
The operating quiescent point is shifted to higher current densities.
Power density of devices has increased significantly: resulting in self-heating effect in power and RF HBTs.
Thermal issue is one of the key factors limiting the performance and reliability of the devices and integrated circuits.
Systematic characterization of thermal effects inside the devices remains very important criteria to explore.
Introduction …
28 June 2011 3/21HiCuM Workshop 2011
Self-heating effect characterization :o Pulse measurementso Low frequency S-parameter measurementso Transient electro-thermal simulation (TCAD)
Calibration and HiCuM compact model simulation
Comparison between single RTH-CTH and recursive electro-thermal network
Outline …
Part 1
Part 2 Electro-thermal scaling rule for Recursive network
Application of scaling on measurements and simulation
28 June 2011 4/21HiCuM Workshop 2011
Pulse measurements …
Bias TEE
RF
DC + RF
RF
DC
DC
DC + RF
R = 50O
R = 50O
Bias TEE
CollectorBias
BaseBias
Base Pulse Generator
Collector Pulse Generator
DUT
P2
P1 • I = Internal resistance of pulse generator• II & IV = Coaxial cables and connectors• III = Bias TEE • V = Open capacitance of DUT
I
II III
IV V
P1/P2 P1T/P2TDUT PORT
o Experimental setup: o Passive elements :
Pulses are applied at Base and Collector terminals simultaneously and the time response of Collector currents are measured.
28 June 2011 5/21HiCuM Workshop 2011
0.00 1.30µ 2.60µ 3.90µ 5.20µ-0.08
-0.04
0.00
0.04
0.08
P1(B
ase)
, P2(
Col
lect
or) P
ulse
(V)
I C (A
)
Time (Sec)
0
1
2
3
4
5
Measurements with optimized condition …
The transient variation of current is due to self-heating effect
Collector Pulse : 5000ns, 1.5 VBase Pulse : 3000ns, 0.95 V
DUT Technology STMicroelectronics BiCMOS9MWGeometry of Emitter window LE x WE = 10 x 0.27Device configuration CBE
28 June 2011 6/21HiCuM Workshop 2011
HiCuM
Model of CoaxialCable-Connector
Model of CoaxialCable-Connector
Model of BiasNetwork
Model of BiasNetwork
Model of CoaxialCable-Connector
T
C
B
Model of CoaxialCable-Connector
P1
P2
E
Pdiss
T
Tground
RTHCTH
HiCuM compact model simulation…
T
Pdiss
Tground
R Kr R Krn R
Kcn CKc CC
Compact model parameter from XMOD Technology
28 June 2011 7/21HiCuM Workshop 2011
T
Pdiss
Tground
R Kr R Krn R
Kcn CKc CC
1( )( )
( ) ( )v
R z z zkA z
C z z C A z z
Δ = Δ
Δ = Δ
Kr (<1) and Kc (>1)
Thermal resistance and capacitance of an elementary volume element at a distance z from heat source with thickness Δz is characterized by C(z)Δz and R(z)Δz as :
z
??
Deep Trench
Shallow TrenchEmitter Window
Collector Contact
dz
Recursive Electro-thermal network…
28 June 2011 8/21HiCuM Workshop 2011Recursive network provides the best accuracy in time domain
Calibration and Electro-thermal modeling …
HiCuM Compact Model
Electro-Thermal Network
Single RTH-CTH
RTH
CTH
Recursive Network
Passive Elements
Pulse Generator internal resistance
Cables + connectors + Device Open Capacitance
Bias Network
0.0 1.0µ 2.0µ 3.0µ 4.0µ 5.0µ 6.0µ
-0.02
0.00
0.02
0.04
0.06
0.08
0.10
0.12
Time (Sec)
I C (A
)
Pulse Measurements
0.0 1.0µ 2.0µ 3.0µ 4.0µ 5.0µ 6.0µ
-0.02
0.00
0.02
0.04
0.06
0.08
0.10
0.12
Time (Sec)
I C (A
)
Pulse Measurements
0.0 1.0µ 2.0µ 3.0µ 4.0µ 5.0µ 6.0µ
-0.02
0.00
0.02
0.04
0.06
0.08
0.10
0.12
Time (Sec)
I C (A
)
Pulse Measurements
0.0 1.0µ 2.0µ 3.0µ 4.0µ 5.0µ 6.0µ
-0.02
0.00
0.02
0.04
0.06
0.08
0.10
0.12
Time (Sec)
I C (A
)
Pulse Measurements
0.0 1.0µ 2.0µ 3.0µ 4.0µ 5.0µ 6.0µ
-0.02
0.00
0.02
0.04
0.06
0.08
0.10
0.12
Time (Sec)
I C (A
)
Pulse Measurements
0.0 1.0µ 2.0µ 3.0µ 4.0µ 5.0µ 6.0µ
-0.02
0.00
0.02
0.04
0.06
0.08
0.10
0.12
Time (Sec)
I C (A
)
Pulse Measurements
10-7 10-6
0.00
0.02
0.04
0.06
0.08
Time (Sec)
I c (Am
p) Pulse Measurements
Extracted with : Single R-C Network Recrusive Network
28 June 2011 9/21HiCuM Workshop 2011
Low frequency S-parameter measurement and thermal modeling
28 June 2011 10/21HiCuM Workshop 2011
Low frequency S-parameter measurements :• 30 kHz – 3 GHz, •VCE = 1.5 V, 1.5 V , VBE = 0.95 V
DUT : L*W = 10*0.27 µm2
104 105 106 107 108 109
1E-4
1E-3
0.01
Frequency (Hz)
Mag
nitu
de (y
12)
MeasuredExtracted with:
Recursive Network Single RC
Low frequency S-parameter measurement and thermal modeling …
104 105 106 107 108 109
1E-4
1E-3
Frequency (Hz)
Mag
nitu
de (y
12)
VCE=1.0 V, VBE=0.95 V VCE=1.5 V, VBE=0.95 V
VCE
Thermal modeling with Single R-C and Recursive electro-thermal network.
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Transient electro-thermal simulation
28 June 2011 12/21HiCuM Workshop 2011
3D electro-thermal transient simulation with TCAD
Taking only lower part of the device including Deep Trench, Shallow Trenchand Thick SiO2 Layer
Transient electro-thermal simulation …
0.00 1.50µ 3.00µ 4.50µ 6.00µ0
5
10
15
20
25
Pow
er (W
att)
Cha
nge
in T
empe
ratu
re (K
)
Time (Sec)
0.00
0.02
0.04
0.06
28 June 2011 13/21HiCuM Workshop 2011
1E-7 1E-6-5.0
0.0
5.0
10.0
15.0
20.0
25.0
Numerical Simulation (TCAD)Extracted with -
Single R-C Network Recrusive Network
Power
Pow
er (W
)
Incr
ease
in T
empe
ratu
re (K
)
Time (Sec)
0.00
0.02
0.04
0.06
0.08
0.10
A pulse of electric power is applied and the transient variation of device temperature has been obtained
The transient temperature variation has been modeled with electro-thermal network
Transient electro-thermal simulation and thermal modeling…
28 June 2011 14/21HiCuM Workshop 2011
The higher value of RTH and the lower value of CTH extracted from numerical simulation can be caused by thermal flux through metal contacts that has not been taken into account.
3 6 9 12 15
1E-11
1E-10
CTH
(Ws/
K)
Emitter Length (μm)
Pulse Measurements Low Frequency S-Parameters
Measurements Numerical Simulations
4 6 8 10 12 14
1500
3000
4500
6000
7500
Emitter Length (μm)
RTH
(K/W
)
Numerical Simulations Pulse Measurements DC Measurements
Parameter extraction for single RTH – CTH network …
28 June 2011 15/21HiCuM Workshop 2011
1 2 3 4 5 6 7 8 9
100
1000
10000
kn rR (
K/W
)
n (number of R-C cell)
Extracted from: Low Frequency S-Parameter Measurements Pulse measurements Transient Simulation
1 2 3 4 5 6 7 8 91E-12
1E-11
1E-10
1E-9
1E-8
1E-7
kn cC (W
s/K
)
n (number of R-C cell)
Extracted from: Low Frequency S-Parameter Measurements Pulse measurements Transient Simulation
LEmitterLEmitter
The overall thermal resistance, RTH = Σ R * kri, where i=0, 1, 2,.. n
T
Pdiss
Tground
R Kr R Krn R
Kcn CKc CC
The resistance and capacitance element of recursive network
Parameter extraction for recursive network …
28 June 2011 16/21HiCuM Workshop 2011
Transient Electro-thermal Scaling rule …
28 June 2011 17/21HiCuM Workshop 2011
Recursive network scaling …
Z tan?+Wemitter/2 Z tan?+Lemitter/2
Z
??
Deep Trench
Shallow TrenchEmitter Window
Collector Contact
( ) ( 2 tan ) ( 2 tan )( ) ( ) , 2tan , 2tan
E E
E E
A z L z W zL aZ W bZ where a b
θ φθ φ
= + ⋅ += + ⋅ + = =
11 1( ) ln
( ) ( )
NN
N N
zzE
E E Ez z
az LdzR z dzA z aW bL bz Wκ κ
++ ⎛ ⎞+
= = ⋅ ⎜ ⎟− +⎝ ⎠∫ ∫
( )( )1
1
( )23 2
( )2
( ) ( )
2 3 66
N N
N N
p
z z
pE E E E z z
C z dz C A z dz
Cabz aW bL z L W z
ρ
ρ+
−
+
+
=
= + + +
∫ ∫
zN -1 zNzm in
T
1
2NNz z ++⎛ ⎞
⎜ ⎟⎝ ⎠
1
2NNz z− +⎛ ⎞
⎜ ⎟⎝ ⎠
zN +1
min exp( )Z Z Nβ=
28 June 2011 18/21HiCuM Workshop 2011
10-8 10-7 10-6 10-5
0
5
10
15
Frequency (Hz)
10-8 10-7 10-6 10-5
0
20
40
ΔT (K
)
ΔT (K
)
Scaling Rule Transient Temperature (TCAD Simulation)…
LE
WE
Symbols TCAD simulation Lines Extracted with scalable electro-thermal network
28 June 2011 19/21HiCuM Workshop 2011
105 106 107 108 109
100
1000
Mag
nitu
de (Z
TH)
Frequency (Hz)
105 106 107 108 109100
1000
10000
Mag
nitu
de (Z
TH)
Scaling Rule Thermal Impedance (TCAD Simulation)…
LE
WE
Symbols TCAD simulation Lines Extracted with scalable electro-thermal network
28 June 2011 20/21HiCuM Workshop 2011
105 106 107 108 109
1E-4
1E-3
Mag
nitu
de(Y
12)
Frequency (Hz)
105 106 107 108 109
1E-5
1E-4
WE= 0.27μm, 0.54μm
0.84μm, 1.08μm
LE= 3μm, 5μm
10μm, 15μm
Mag
nitu
de(Y
12)
105 106 107 108 109-3.0
-2.5
-2.0
-1.5
-1.0
-0.5
0.0
Phas
e(Y
12) (
degr
ee)
Frequency (Hz)
105 106 107 108 109-2.0
-1.5
-1.0
-0.5
0.0
WE= 0.27μm, 0.54μm
0.84μm, 1.08μm
LE= 3μm, 5μm
10μm, 15μm
Phas
e(Y
12) (
degr
ee)
Scaling Rule Thermal modeling of Y-parameter…
LELE
WEWE
Symbols MeasurementsLines Compact model simulation with scalable electro-thermal network
DUT Technology STMicroelectronics BiCMOS9MWDevice configuration CBEBC
28 June 2011 21/21HiCuM Workshop 2011
The transient electro-thermal effect has been characterized with pulse measurements and verified through S-Parameter measurements and transient simulations.
The extraction of CTH parameter for small device dimension can be achieved by employing a complete calibration.
Two different electro-thermal networks have been compared to demonstrate time domain thermal spreading impedance.
The scaling behavior of transient electro-thermal phenomena has been investigated and verified through measurements and simulations.
Thank you
Conclusions …