UTMOST
Data Acquisition and Parameter Extraction
Features
● Comprehensive device characterization
and modeling capabilities
● Supports a wide range of measurement
equipment and probers
● Fully interactive, semi-automatic, or
batch-mode operation
● Step-and-repeat operation including
wafer cassette control
● DC, AC, transient, and capacitance test
routines
● MOSFET, BJT, Diode, JFET, GaAs, SOI,
TFT, and HBT modules
● Interfaces to process and device UTMOST is a data acquisition and parameter
simulators and to the SPAYN statistical extraction tool with applications in the areas
parameter analysis tool of device characterization and modeling.
● Supports a wide variety of models and
circuit simulators
Data Acquisition and Parameter Extraction Tool
UTMOST is a general purpose data acquisition and parameter extraction tool. UTMOST can control a very wide range of commercial
measurement hardware and probers so that the UTMOST user has maximum flexibility in the configuration of a measurement test system.
UTMOST has many unique features which allow detailed analyses of both device characteristics and model behavior. UTMOST can be
used in a fully interactive mode but various levels of automation, including a full batch-mode capability, are also offered.
Discrete devices, multi-geometry test modules, entire wafers, or wafer batches may be tested using UTMOST. Parameter extraction
based on DC, AC, transient or capacitance measurements is supported for MOSFET, BJT, Diode, JFET, GaAs, SOI, TFT, and HBT devices.
UTMOST now features seamless links to other Silvaco products including ATHENA (process simulation), ATLAS (device simulation),
SPAYN (worst-case model development), and SmartSpice (circuit simulation). UTMOST supports commercial device models, user-defined
device models and macro models. Direct communication with the models in most popular commercial circuit simulators is also supported.
Test and Analysis Environment
UTMOST is designed to address the practical needs of device
characterization and parameter extraction engineers in the most
flexible manner possible. This is evident from the functionality
of the software as well as from the impressive list of supported
instrument drivers, prober drivers, device models, operating
platforms, and commercial circuit simulators. UTMOST allows
the device characterization or modeling problem to be split
into separate measurement and analysis tasks. Measured
results can be stored in special UTMOST measurement Log files
for future analysis so that valuable probe time is minimized. Many
UTMOST routines, such as ALL_DC, are very general purpose in
nature which means that the same data sets can be used for the
extraction of parameters from different models.
Single test or step-and-repeat operation is fully supported by
UTMOST and its Log files. Parameter extractions may be performed
using a comprehensive library of built-in extraction algorithms,
flexible user-defined local optimization strategies, more interactive
global optimization procedures, or a combination of all three. UTMOST
measurement Log files have search features for identifying measured
routines and devices. Parameters extracted by UTMOST can be
UTMOST Parameter Extraction
stored in many formats, one of the most useful of which is the
SPICE library format. SPICE libraries created by UTMOST are UTMOST has many in-built parameter extraction routines
suitable for use in circuit simulators. SPICE libraries may be which were developed for the extraction of both process-monitor
searched by UTMOST and a selected model can be read back into and device model parameters. Fully flexible local optimization
UTMOST as an initial estimate during future parameter extractions. strategies, for any supported model, can also be implemented in
UTMOST. These local optimization procedures may be used
● Flexible measurement environment definition
instead of, or as a supplement to, the in-built extraction schemes
● Flexible analysis environment definition
for the UTMOST routine in use.
● Extraction, local optimization, and global
optimization methods For bipolar devices there are extraction routines supplied to
● Measurement Log file option extract resistance, breakdown, saturation, temperature, leakage,
forward and reverse gain, early voltage, knee current, and basic
● Log file search and averaging capabilities
Gummel-Poon parameters from DC measured characteristics.
● SPICE library input, output, and search options Extraction routines for cut off frequency, forward and reverse
transit time, base resistance, and excess phase parameters are
implemented for s-parameter measurements. UTMOST can also
UTMOST Data Acquisition extract bipolar junction capacitance parameters from the capacitance
data that it measures. UTMOST includes routines for the extraction
of many DC MOSFET parameters including length reduction,
width reduction, threshold voltage, low-field mobility, body effect,
velocity saturation, resistance, breakdown, and subthresh-
old slope parameters. Based on MOSFET module experi-
ence the SOI module permit the characterization of all tran-
sistor properties, including 4/5 terminals device, bipolar
parasitic effects, Body or BackGate currents.
Measured s-parameters can be converted to h, z, and
y-parameters. Standard, one step and two step, de-embedding
procedures are supported by UTMOST to aid in the deter-
mination of MOSFET s-parameters. In addition, UTMOST
supports the extraction of overlap and junction capacitances
from capacitance measurements. Special extraction algorithms
for the extraction of BSIM1, BSIM2, BSIM3 and MOS9 parameters,
One of the main strengths of UTMOST is the fact that it can drive for single or multiple geometries, are also included in UTMOST.
most commonly used DC analyzers, AC analyzers, capacitance
A new Universal multitarget / multigeometry measurement
meters, switching matrix controllers, pulse generators, and
oscilloscopes. UTMOST also controls most commercial automatic routine is available for SOI and MOS technology.
and semi-automatic probers. In addition, UTMOST includes
drivers for many temperature ovens and hot chucks. Elaborate
computer controlled test systems can be configured using
UTMOST. DC, capacitance, transient, or s-parameter measurements
can be performed on packaged devices, on a wafer, or in wafer
stepping mode. UTMOST will also accept data measured by
Keithley 450 and Reedholm parametric test systems.
DC Analyzers AC Analyzers Scanners
HP4145 HP8510A,B,C HP4084
HP4141 HP8720A,B,C,D,E HP4085
HP4142 HP8753A,B,C,D,E HP4086
HP4155/56 HP3577 HP3488
Keithley 236 HP8505 HP3495
Keithley 237 HP8754 HP3852A
Keithley 238 HP8751 Keithley 705
Keithley S450 Wiltron 360 Keithley 706
Tektronics 370/370A HP8722D Keithley 707
Tektronics 371/371A Keithley 7002
RACAL 1251
Capacitance Meters Probers
HP4284,HP4285 Electroglas 1034
HP4262 RK 680
HP4271 RK 681
HP4192 Cascade Summit
HP4275,HP4276,HP4277 Alessi 5500
HP4274 TKS 4000
HP4280 TKS 6000
HP4194 Tokyo Electron
HP4279 Electroglas 2001
Keithley 590 RK 1032
Keithley 595 Alessi 4500
Karl Suss (PE100/PA200 II)
TKS 3000
TKS 5000
Wentworth MP-1100
This routine based on full SMU definition, permit to define 12 On the other side, the Downhill Simplex method is very easy to
different bias conditions and is especially written to extract all use and keep the physical meaning of the spice parameters. As
kind of characteristics. Simulation, Macro Modeling, local and this second methodology is based on a very simple theory, it is
global optimization are available. very easy to understand and do not have any parameters so
complicated as the Levenberg-Marquardt one.
● Numerous built-in DC extraction routines
● BSIM1, BSIM2 and BSIM3 parameter extraction algorithms One efficient solution is to use the both methods when the first
● Global and local parameter optimization chosen do not give acceptable results.
● s-parameter measurements This new feature will allow to perform better and faster optimizations.
● DC, AC, transient and capacitance extraction routines ● Rubberband interactive parameter extraction
● s-parameter to h, z, or y-parameter conversion ● Multi-geometry optimization
● Multi-step optimization
● Optimization boundary boxes
UTMOST Parameter Optimization
● Flexible local optimization facility
● Graphical parameter sensitivity and error history information
UTMOST Model Features
UTMOST supports most commercially available device models.
Models are treated in three different ways by UTMOST. The
three choices of model definition are called External SPICE,
SmartLib, and Internal Models. Models equations which are
accessed through whatever circuit simulator is in use are called
External SPICE Models. Interpreted models in SmartSpice are
also treated as External SPICE models. Any models which exist
in SmartSpice, or user-defined models which have been linked
dynamically, and stored as external libraries with a special fast
solver, are called SmartLib Models. Models which have been
hard coded into UTMOST are called Internal Models. The effects
on simulated device characteristics of the model parameters
associated with any SmartLib Model can be viewed with the
Rubberband option. As such, the Rubberband facility is a very
useful educational tool.
UTMOST supports the conversion of model parameter sets from
one model to another. This is invaluable in situations where the
model in use has changed and new parameter sets are needed
without the requirement of measuring new data. Devices which
The use of optimization techniques to extract model parameters cannot be adequately modeled by any existing device models
is unavoidable for many device models. Dedicated fitting routines may require the use of macro models. UTMOST supports the use
do not always result in the required level of model accuracy and of macro models and the extraction of the macro model parameters.
in these situations parameter optimization is often used as a means UTMOST supports the simulation of DC, transient, capacitance
of model refinement. The very useful Rubberband option is often and s-parameter characteristics. A list of some of the models
used by UTMOST users to help define suitable initial parameter which are supported by the UTMOST external libraries are
guesses for the model and data under analysis. The Rubberband shown here. Commercial circuit simulators can be directly linked
option allows the user to see the effects of parameter variations to UTMOST and any models supported by these simulators can
on device characteristics in a visually interactive manner. be accessed by UTMOST.
UTMOST offers both local and global parameter optimization
options. Both options allow for the optimization of multiple
device geometries simultaneously (up to 36 devices) and both
options allow for the mixed use of device currents and conductances
as optimization targets. The regular optimization facility offers
single or multi-geometry graphical updating of the simulated
characteristics, the definition of graphical optimization boundary
boxes, and the generation of parameter sensitivity and error history
information. Local optimization allows the user to define and
store flexible multiple step parameter optimization strategies.
The target ranges of currents or conductances can be explicitly
defined and the optimization execution is very fast.
Optimization in UTMOST could be achieved using two
methodologies. First the well known and robust Levenberg-
Marquardt which required the computation of the first and sec-
ond derivatives. The method converge quickly but is, in most of
cases, very dependant of the initial values of the parameters.
● Model investigation using the Rubberband tool
● Models accessible through circuit simulator
● Macro modeling
● User-defined models linked dynamically
● Support for SmartSpice interpreter models
● Supports large number of commercial device models, some of
which are listed below
● Fast simulation using SmartLib Model and Fast internal solver
MOSFET models Bipolar models SOI model MESFET model
Berkeley Level 1 Gummel-Poon Honeywell JFET
Berkeley Level 2 Quasi RC FLORIDA FD Statz
Berkeley Level 3 IGBT FLORIDA NFD Curtice 1
BSIM1 QBBJT BSIM3SOI FD Curtice 2
BSIM2 MEXTRAM BSIM3SOI DD User models
BSIM3 HBT BSIM3SOI PD
Philips Level 9 HICUM STAG SOI
EKV MEXTRAM504 CEA/LETI TFT models
MASTAR User models User models Amorphous TFT
BSIM4
Philips Level 11
Polysilicon TFT
RPI a-Si
Flexible Device Characterization and
User models RPI p-Si Spice Modeling
The most important test structures for any IC manufacturing
UTMOST Operation process are the devices themselves. It is imperative that these
devices are sufficiently characterized so that important informa-
UTMOST can be used in manual, semi-automatic, automatic, or tion regarding device performance, model performance, and the
batch modes of operation. The selection of the mode of operation best model parameter set for the device under test can be extract-
will depend on the needs of the user. Detailed first-time analysis ed. UTMOST is the ideal tool for these critical tasks. UTMOST
will be best served by a totally manual analysis. Predefined tests can accept data from direct measurements, measurements stored
and analyses, especially step-and-repeat tests, should require in a measurement Log file, process and device simulation, or
semi-automatic or fully automatic UTMOST operation. Abatch-mode from other model parameter sets in order to create a suitable
option is offered to users who wish to analyze measured parameter set for the chosen model. UTMOST supports most of
UTMOST Log files using a command-line language and no the commonly used measurement and prober hardware and is
graphical user interface. This may be done to speed up an analysis or available on many platforms.
to reduce the user interactivity to a minimum.
UTMOST currently has eight technology modules namely MOS, SPECIFICATIONS:
Bipolar, Diode, JFET, GaAs, SOI, TFT, and HBT which are usually Equipment Probers Circuit Simulators
run separately. To cater for situations where it is necessary to TM
Hewlett Packard Electroglas SmartSpice
measure device characteristics for devices of different types in Keithley Rucker-Koll
TM
HSpiceTM
the same test run, a PROMOST module has been developed. Tektronics Cascade-Summit PSpice TM
Batch-mode UTMOST commands are fully supported by Wiltron TKS Spectre
TM
TEL Saber TM
SILVACO’s Virtual Wafer Fab (VWF) product. Using batch-mode Karl Suss ELDO
UTMOST, device characteristics resulting from process and Wentworh
device simulations can be automatically converted into Alessi
UTMOST format, and detailed parameter extractions can be per-
formed. In this way it is possible to develop nominal and even process
recipes process/device/SPICE
worst-case models for a process which is under development. VWF model parameters
SPICE model, circuit test,
process monitor, electrical
characteristics
device
Model parameters and device characteristics can be stored in electrical test/SPICE
model parameters SPAYN
test parameters
SPAYN format. Statistical parametric analysis and worst-case
parameters
user-defined, nominal,
model definitions can be performed by SPAYN on this data. Monte Carlo, corner,
model
model parameters
● Manual, semi-automatic, automatic, and batch mode SPICE model SPICE input SmartSpice
parameters files
operation measured
UTMOST
characteristics
worst-case
nominal &
device simulated
characteristics VYPER device & circuit
● MOS, Bipolar, Diode, JFET, GaAs, SOI, TFT, and HBT simulated device &
circuit characteristics
characteristics
technology modules
circuit netlist & control statements
● PROMOST mixed technology measurement module
Supported Platforms
● UTMOST batch-mode operation under VWF
SUN SunOS 4.1.4 HP HPUX 10.20
● SPAYN output option Solaris 2
DEC OSF/1 3.2 IBM AIX 4.1.4
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USA Silvaco Germany
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sales@silvaco.com
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