LEVEL 6 Philips Bipolar Model (MEXTRAM LEVEL 504)
The new version of the MEXTRAM model has been added to Star-Hspice as BJT LEVEL 6. You can now specify the VERS parameter to choose MEXTRAM level 503 or 504. The default value of the VERS parameter is 504.
MEXTRAM 504 gives better results for the description of first and higher-order characteristic derivatives than MEXTRAM 503. This effect is noticeable in the output-conductance, the cut-off frequency, and the low-frequency third order distortion.
The MEXTRAM LEVEL 504 covers several effects that are not included in the original Gummel-Poon model. These effects include:
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Temperature
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Charge storage
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Substrate
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Parasitic PNP
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High-injection
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Bias-dependent early effect
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Low-level, non-ideal base currents
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Hard- and quasi-saturation (including Kirk Effect)
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Weak avalanche (optionally including snap-back behavior)
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Explicit modeling of inactive regions
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Split base-collector and base-emitter depletion capacitance
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Current crowding and conductivity modulation of the base resistance
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First order approximation of distributed high frequency effects in the intrinsic base (high frequency current crowding and excess phase shift)
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Ohmic resistance of epilayer
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Velocity saturation effects on the resistance of the epilayer
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Recombination in the base (meant for SiGe transistors)
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Early effects in the case of a graded bandgap (SiGe)
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Thermal noise, shot noise, and 1/f-noise
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Self-heating
The description for this model can be found at:
http://www.semiconductors.philips.com/Philips_Models/newsflash/mextram504
Notes for HSPICE Users
The following information should be considered when using MEXTRAM 504 with Hspice:
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Set Level 6 to identify the model as a MEXTRAM bipolar junction transistor model
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Set VERS parameter to 503 to use MEXTRAM 503
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Set VERS parameter to 504 to use MEXTRAM 504
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Consider that all internal resistors are limited to greater than or equal to 1.0e-6
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Reference temperature, TREF, is equal to 25 degrees
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MEXTRAM does not contain extensive geometrical or process scaling rules (it has a multiplication factor to put transistors in parallel)
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MEXTRAM does not contain a substrate resistance
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Constant overlap capacitances are not modelled within MEXTRAM
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MEXTRAM 504 has better convergence than 503
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MEXTRAM is more complex than Gummel-Poon (the computation time will be longer and the convergence will be less)
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No reverse emitter-base breakdown mechanism
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Forward current of the parasitic PNP transistor is modelled
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Output conductance dIc/dVce at the point where hard saturation starts seems to be too abrupt for high current levels, compared to measurements
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Clarity of extrinsic current model describing Xiex and Xisub could be improved by adding an extra node and an extra contact base resistance. In this case, parameter extraction would be more difficult
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Self-heating is not enabled for this model, so model parameters RTH and CTH have no influence
LEVEL 6 Model Parameters (504)
The following tables describe MEXTRAM 504 as LEVEL 6 model parameters including parameter name, unit, default, description and notes.
TAUNE in MEXTRAM 503 acts as TAUE in the 504 model.
Parameters noted with a `*' are not used in the DC model.
The following nine parameters are deleted from MEXTRAM 503:
The following 18 parameters have been added to MEXTRAM 504:
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TAUE
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TAUB
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TEPI
-
TAUR
-
DEG
-
XREC
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Flags
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Parameter
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Unit
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Default
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Description
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LEVEL
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-
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6
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Model level
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VERS
|
-
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504
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Flag for choosing MEXTRAM model (level 503 or 504)
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EXMOD
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-
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1
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Flag for extended modeling of the reverse current gain
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EXPHI
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-
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1
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*Flag for distributed high frequency effects in transient
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EXAVL
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-
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0
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Flag for extended modeling of avalanche currents
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TREF
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^C
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25.0
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Reference temperature
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Basic Parameters
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Parameter
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Unit
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Default
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Description
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IS
|
A
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2.2e-17
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Collector-emitter saturation current
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VER
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2.5
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Reverse early voltage
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VEF
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44.0
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Forward early voltage
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BF
|
-
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215.0
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Ideal forward current gain
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XIBI
|
-
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0.0
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Fraction of ideal base current that belongs to the sidewall
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IBF
|
A
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2.7e-15
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Saturation current of the non-ideal forward base current
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MLF
|
V
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2.0
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Non-ideality factor of the non-ideal forward base current
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IK
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A
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0.1
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Collector-emitter high injection knee current
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BRI
|
-
|
7.0
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Ideal reverse current gain
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IBR
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A
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1.0e-15
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Saturation current of the non-ideal reverse base current
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VLR
|
V
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0.2
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Cross-over voltage of the non-ideal reverse base current
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XEXT
|
-
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0.63
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Part of Iex, Qex, Qtex, and Isub that depends on the base-collector voltage Vbc1
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Avalanche Model Parameters
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Parameter
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Unit
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Default
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Description
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WAVL
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m
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1.1e-6
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Epilayer thickness used in weak-avalanche model
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VAVL
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V
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3.0
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Voltage determining the curvature of avalanche current
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SFH
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-
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0.3
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Current spreading factor of avalanche model (when EXAVL=1)
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Resistance and Epilayer Parameters
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Parameter
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Unit
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Default
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Description
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RE
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Ohm
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5.0
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Emitter resistance
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RBC
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Ohm
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23.0
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Constant part of the base resistance
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RBV
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Ohm
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18.0
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Zero-bias value of the variable part of the base resistance
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RCC
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Ohm
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12.0
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Constant part of the collector resistance
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RCV
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Ohm
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150.0
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Resistance of the un-modulated epilayer
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SCRCV
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Ohm
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1250.0
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Space charge resistance of the epilayer
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IHC
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A
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4.0e-3
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Critical current for velocity saturation in the epilayer
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AXI
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-
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0.3
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Smoothness parameter for the onset of quasi-saturation
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Base-Emitter Capacitances
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Parameter
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Unit
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Default
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Description
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CJE
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F
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7.3e-14
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*Zero bias emitter-base depletion capacitance
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VDE
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V
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0.95
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Emitter-base diffusion voltage
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PE
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-
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0.4
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Emitter-base grading coefficient
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XCJE
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-
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0.4
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*Fraction of the emitter-base depletion capacitance that belongs to the sidewall
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Base-Collector Capacitances
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Parameter
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Unit
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Default
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Description
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CJC
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F
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7.8e-14
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*Zero bias collector-base depletion capacitance
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VDC
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V
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0.68
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Collector-base diffusion voltage
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PC
|
-
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0.5
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Collector-base grading coefficient
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XP
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-
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0.35
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Constant part of CJC
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MC
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-
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0.5
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Coefficient for the current modulation of the collector-base depletion capacitance
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XCJC
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-
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3.2e-2
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*Fraction of the collector-base depletion capacitance under the emitter
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Transit Time Parameters
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Parameter
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Unit
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Default
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Description
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MTAU
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-
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1.0
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*Non-ideality of the emitter stored charge
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TAUE
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S
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2.0e-12
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*Minimum transit time of stored emitter charge
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TAUB
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S
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4.2e-12
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*Transit time of stored base charge
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TEPI
|
S
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4.1e-11
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*Transit time of stored epilayer charge
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TAUR
|
S
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5.2e-10
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*Transit time of reverse extrinsic stored base charge
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DEG
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EV
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0.0
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Bandgap difference over the base
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XREC
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-
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0.0
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Pre-factor of the recombination part of Ib1
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Temperature Parameters
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Parameter
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Unit
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Default
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Description
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AQBO
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-
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0.3
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Temperature coefficient of the zero-bias base charge
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AE
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-
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0.0
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Temperature coefficient of the resistivity of the emitter
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AB
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-
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1.0
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Temperature coefficient of the resistivity of the base
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AEPI
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-
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2.5
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Temperature coefficient of the resistivity of the epilayer
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AEX
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-
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0.62
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Temperature coefficient of the resistivity of the extrinsic base
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AC
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-
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2.0
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Temperature coefficient of the resistivity of the buried layer
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DVGBF
|
V
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5.0e-2
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Bandgap voltage difference of forward current gain
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CVGBR
|
V
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4.5e-2
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Bandgap voltage difference of reverse current gain
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VGB
|
V
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1.17
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Bandgap voltage of the base
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VGC
|
V
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1.18
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Bandgap voltage of the collector
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VGJ
|
V
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1.15
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Bandgap voltage recombination emitter-base junction
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DVGTE
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V
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0.05
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*Bandgap voltage difference of emitter stored charge
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Noise Parameters
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Parameter
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Unit
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Default
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Description
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AF
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-
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2.0
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Exponent of the flicker-noise
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KF
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-
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2.0e-11
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Flicker-noise coefficient of the ideal base current
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KFN
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-
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2.0e-11
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Flicker-noise coefficient of the non-ideal base current
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Substrate Parameters
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Parameter
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Unit
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Default
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Description
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ISS
|
A
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4.8e-17
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Base-substrate saturation current
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IKS
|
A
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2.5e-4
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Base-substrate high injection knee current
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CJS
|
F
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3.15e-13
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*Zero bias collector-substrate depletion capacitance
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VDS
|
V
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0.62
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*Collector-substrate diffusion voltage
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PS
|
-
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0.34
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*Collector-substrate grading coefficient
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VGS
|
V
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1.2
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Bandgap voltage of the substrate
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AS
|
-
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1.58
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For a closed buried layer: AS=AC
For an open buried layer: AS=AEPI
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Self-Heating Parameters
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Parameter
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Unit
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Default
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Description
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RTH
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^C/W
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300.0
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Thermal resistance
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CTH
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J/^C
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3.0e-9
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*Thermal capacitance
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MEXTRAM Level 504 DC OP Analysis Example
**** DC OP analysis of mextram 504 model ****
.OPTIONs GMIN=1.0e-13
Q1 1 2 3 4 m504 area=1 m=1
* Start sources
VB 2 0 DC 1.2
VC 1 0 DC 2.2
VE 3 0 DC 0.0
VS 4 0 DC 0.0
.DC VB 0.4 1.2 0.1
.DC VC 1.4 2.2 0.1
.op
.PRINT DC I(VC) I(VB) I(VE) I(VS)
.TEMP 25
.Model m504 npn level=6
+ VERS = 504
+ TREF = 25.0
+ EXMOD = 1.0
+ EXPHI = 1.0
+ EXAVL = 0.0
+ IS = 22.0E-18
+ IK = 0.1
+ VER = 2.5
+ VEF = 44.0
+ BF = 215.0
+ IBF = 2.7E-15
+ MLF = 2.0
+ XIBI = 0.0
+ BRI = 7.0
+ IBR = 1.0e-15
+ VLR = 0.2
+ XEXT = 0.63
+ WAVL = 1.1E-6
+ VAVL = 3.0
+ SFH = 0.3
+ RE = 5.0
+ RBC = 23.
+ RBV = 18.
+ RCC = 12.
+ RCV = 150.
+ SCRCV = 1250.0
+ IHC = 4.e-3
+ AXI = 0.3
+ CJE = 73.0e-15
+ VDE = 0.95
+ PE = 0.4
+ XCJE = 0.4
+ CJC = 78.0E-15
+ VDC = 0.68
+ PC = 0.5
+ XP = 0.35
+ MC = 0.5
+ XCJC = 32.E-3
+ MTAU = 1.0
+ TAUE = 2.0E-12
+ TAUB = 4.2E-12
+ TEPI = 41.E-12
+ TAUR = 520.E-12
+ DEG = 0.01
+ XREC = 0.1
+ AQBO = 0.3
+ AE = 0.0
+ AB = 1.0
+ AEPI = 2.5
+ AEX = 0.62
+ AC = 2.0
+ DVGBF = 0.05
+ DVGBR = 0.045
+ VGB = 1.17
+ VGC = 1.18
+ VGJ = 1.15
+ DVGTE = 0.05
+ AF = 2.0
+ KF = 2.E-11
+ KFN = 2.E-11
+ ISS = 48.E-18
+ IKS = 250.E-6
+ CJS = 315.E-15
+ VDS = 0.62
+ PS = 0.34
+ VGS = 1.20
+ AS = 1.58
.END
MEXTRAM Level 504 Transient Analysis Example
*** Transient analysis of Mextram 504 model ***
.options gmin=1e-13 dccap POST=1
QCKT 1 2 0 0 m504 area=1.0 m=1
* START SOURCES
VC 3 0 DC 2
VB 2 0 DC 0 PULSE (0 0.8 0 1n 1n 10n 25n)
R 1 3 0.1
.temp 100
.TRAN 10p 50n
.op
.PRINT tran I(VC) I(VB)
.Model m504 npn level=6
+ VERS = 504
+ TREF = 25.0
+ EXMOD = 1.0
+ EXPHI = 1.0
+ EXAVL = 0.0
+ IS = 22.0E-18
+ IK = 0.1
+ VER = 2.5
+ VEF = 44.0
+ BF = 215.0
+ IBF = 2.7E-15
+ MLF = 2.0
+ XIBI = 0.0
+ BRI = 7.0
+ IBR = 1.0e-15
+ VLR = 0.2
+ XEXT = 0.63
+ WAVL = 1.1E-6
+ VAVL = 3.0
+ SFH = 0.3
+ RE = 5.0
+ RBC = 23.
+ RBV = 18.
+ RCC = 12.
+ RCV = 150.
+ SCRCV = 1250.0
+ IHC = 4.e-3
+ AXI = 0.3
+ CJE = 73.0e-15
+ VDE = 0.95
+ PE = 0.4
+ XCJE = 0.4
+ CJC = 78.0E-15
+ VDC = 0.68
+ PC = 0.5
+ XP = 0.35
+ MC = 0.5
+ XCJC = 32.E-3
+ MTAU = 1.0
+ TAUE = 2.0E-12
+ TAUB = 4.2E-12
+ TEPI = 41.E-12
+ TAUR = 520.E-12
+ DEG = 0.01
+ XREC = 0.1
+ AQBO = 0.3
+ AE = 0.0
+ AB = 1.0
+ AEPI = 2.5
+ AEX = 0.62
+ AC = 2.0
+ DVGBF = 0.05
+ DVGBR = 0.045
+ VGB = 1.17
+ VGC = 1.18
+ VGJ = 1.15
+ DVGTE = 0.05
+ AF = 2.0
+ KF = 2.E-11
+ KFN = 2.E-11
+ ISS = 48.E-18
+ IKS = 250.E-6
+ CJS = 315.E-15
+ VDS = 0.62
+ PS = 0.34
+ VGS = 1.20
+ AS = 1.58
.END
MEXTRAM Level 504 AC Analysis Example
*** AC analysis of Mextram 504 model ***
.options gmin=1e-13 POST=1 converge=1 relv=1.e-6 absv=1.e-9
QCKT 11 22 33 44 m504 area=1.0 m=1
* START SOURCES
VE 3 0 DC 0
VB 2 0 DC 0.7
VC 1 0 DC 1.0
VS 4 0 DC 0
.DC VB 0.7 1.0 0.02
.ac dec 1 1.e4 1.e11
vc1 11 1 0
vb1 22 2 0 ac=0.001
ve1 33 3 0
vs1 44 4 0
.op
.print ac ir(vc1) ii(vc1) ir(vb1) ii(vb1)
.temp 25
.Model m504 npn level=6
+ VERS = 504
+ TREF = 25.0
+ EXMOD = 1.0
+ EXPHI = 1.0
+ EXAVL = 0.0
+ IS = 22.0E-18
+ IK = 0.1
+ VER = 2.5
+ VEF = 44.0
+ BF = 215.0
+ IBF = 2.7E-15
+ MLF = 2.0
+ XIBI = 0.0
+ BRI = 7.0
+ IBR = 1.0e-15
+ VLR = 0.2
+ XEXT = 0.63
+ WAVL = 1.1E-6
+ VAVL = 3.0
+ SFH = 0.3
+ RE = 5.0
+ RBC = 23.
+ RBV = 18.
+ RCC = 12.
+ RCV = 150.
+ SCRCV = 1250.0
+ IHC = 4.e-3
+ AXI = 0.3
+ CJE = 73.0e-15
+ VDE = 0.95
+ PE = 0.4
+ XCJE = 0.4
+ CJC = 78.0E-15
+ VDC = 0.68
+ PC = 0.5
+ XP = 0.35
+ MC = 0.5
+ XCJC = 32.E-3
+ MTAU = 1.0
+ TAUE = 2.0E-12
+ TAUB = 4.2E-12
+ TEPI = 41.E-12
+ TAUR = 520.E-12
+ DEG = 0.01
+ XREC = 0.1
+ AQBO = 0.3
+ AE = 0.0
+ AB = 1.0
+ AEPI = 2.5
+ AEX = 0.62
+ AC = 2.0
+ DVGBF = 0.05
+ DVGBR = 0.045
+ VGB = 1.17
+ VGC = 1.18
+ VGJ = 1.15
+ DVGTE = 0.05
+ AF = 2.0
+ KF = 2.E-11
+ KFN = 2.E-11
+ ISS = 48.E-18
+ IKS = 250.E-6
+ CJS = 315.E-15
+ VDS = 0.62
+ PS = 0.34
+ VGS = 1.20
+ AS = 1.58
.END
Star-Hspice Manual - Release 2001.2 - June 2001
