VisualTCAD 1.8.0-1

2014.3.22

After several beta releases to selected customers, this is the major upgrade with new tools and new features.

Genius Device Simulator

  • Modeling of carrier quantum confinement using the density-gradient model. This model is applicable, for example, to the 2DEG of the inversion layer in MOSFET transistors.
  • Device-circuit mixed simulation using the Schur-complement numerical solver, which significantly enhances the convergence when non-trivial circuits are involved.
  • Improved impact-ionization model which avoids unphysical solutions, and achieves better convergence at the same time.
  • Self-consistent gate tunneling current model, in which tunneling current is coupled with the carrier continuity equation.
  • Mobility and other material property models which matches with another popular TCAD tool for selected materials.
  • New solver for the 3D analysis of satellite internal-charging problem.
  • Over 200 other minor features and bug fixes.

GSeat Particle Simulator

  • Upgrade to Geant4.9.6
  • New program (geds) for electron transport simulation in the 3D analysis of satellite internal-charging problem.
  • The SSAT and mulassis programs are bundled.
  • New utility for GDML model creation and manipulation. Examples of creating detailed model of BGA IC package.
  • New utility for fast integration of energy deposition in sensitive volumes in a single device or in a cell array.
  • Improved support of biasing for elastic collisions of heavy ions.

CRad Space Radiation Environment and Effects Analysis

  • Models of radiation environments in space
    • Spacecraft orbit
    • Geomagnetic field
    • Geomagnetic trapped radiation
    • Galactic cosmic rays and anomalous cosmic rays
    • Solar energetic particles (short-term flux and cumulative fluence)
    • Geomagnetic shielding
  • Transport through spacecraft walls and other shieldings
  • Radiation effects in microelectronics
    • Total-ionization dose and dose-depth calculation
    • Non-ionizing energy loss (NIEL) calculation
    • Single-event upset rate calculation for proton and heavy ions
    • Composite sensitive volume model

VisualTCAD 1.7.4-14

2013.3.19

This is a bug-fix release.

Genius Device Simulator

  • Lag-LU preconditioner is now stable.
  • Fix slowness mixed-mode simulation due to insufficient memory allocation.
  • Fix a bug in synchronizing the volume of mesh elements across processors.
  • Several fixes to protect mathematical functions from overflow/underflow.
  • Better support importing Medici TIF file.
  • Operation-point solution is saved to '*.op.dat' to avoid overwriting other solution files.

VisualTCAD GUI

  • Support importing TIF file produced by Suprem4/TSuprem4 in 2D Device drawing, for re-meshing.
  • Fix mesh generator crash due to floating-point number rounding error.
  • Avoid crashing when reading malformed TIF3D mesh file.
  • Support reading user-defined profile in TIF3D file.

Gds2mesh

  • Allow user to define custom field variables, and specify their units.
  • Each physical volume in exported GDML now has a distinct name.
  • The material of the "World" physical volume in exported GDML is changed to Vacuum.
  • Remove degenerate polygons in GDSII layout.

VisualTCAD 1.7.4-10

2012.11.27

This is a bug-fix release.

Genius Device Simulator

  • Display units of physical quantities in vtk output files.
  • Allow user to set the convergence criteria of operation-point solution.
  • Fix occasional crash due to uninitialized variable in external circuit solver.
  • Fix boundary detection when seconductor region is in contact with many insulator regions.

VisualTCAD GUI

  • Improve font display on some Linux systems.
  • Improve compatibility with TMA TIF mesh format.
  • Display units of physical quantities in vtk output files.
  • Added support for dose-rate radiation effect analysis.
  • Fix a bug that causes button not being functional on some Linux platform.
  • Fix a bug that leads to crash when a vtk/cgns file contains unrecognized material.

VisualTCAD 1.7.4-8

2012.10.08

This is a bug-fix release.

Genius Device Simulator

  • Experimental option to use Lag-LU preconditioner, improves the speed of DDM solver by up to 2x.
  • Improves convergence when a mesh edge has negative FVM cross-section area.
  • Fix the incomplete implementation of the resistive-metal/insulator interface in small-signal AC simulation.
  • Fix an error in mole fraction setting in parallel simulation.
  • Fix numerical trunction error in ray-tracing optics, when light source is far from the device.

GSeat Particle Simulator

  • Enabled elastic hadron processes for alpha particle and general ions.
  • Fix crashing error when HDF5 output filename is not supplied by user.

VisualTCAD GUI

  • Fix linear mole fraction profile seetting in GUI.
  • Misc. fixes in AC simulation setup in GUI.
  • Fix waveform display in voltage/current source setings.

VisualTCAD 1.7.4-5

2012.08.02

This is a bug-fix release.

Supported Platforms

  • Experimental support for Debian 7 (Wheezy/sid) x86_64 Linux platform. It is built and tested on Ubuntu 12.04LTS.

Genius Device Simulator

  • Fix synchronization of the boundary-proximity flag of mesh nodes, which affects surface mobility calculation.
  • Improves mesh element truncation scheme, reduces fluctuation when mesh elements near interfaces have poor quality.
  • Fix mesh element truncation rule mismatch. The same rule must be used in semiconductor and metal regions.
  • Improves convergence when EQF is used as parallel E-field in mobility calculation.
  • Fix importing TIF mesh file produced by the MEDICI program.

VisualTCAD GUI

  • Support syntax-highlighting in scripting window in VisualFab.
  • Fix specification of mole fraction of two compound semiconductor materials.
  • Miscellaneous fixes.

VisualTCAD 1.7.4-3

2012.07.10

This is a bug-fix release.

Genius Device Simulator

  • Fix default direct linear solver in serial mode.
  • Fix unit of dopant concentration in RegionSet command.

VisualTCAD GUI

  • Fix a bug in principal optical axes setting for 2D structure.
  • Fix a bug in netlist topology calculation in schematic editor.
  • Minor fixes in Windows installer, improve support for Flexlm.

VisualTCAD 1.7.4-2

2012.06.24

This is a bug-fix release, with some user manual updates.

Genius Device Simulator

  • General
    • Fix large memory consumption during importing the carrier generation profile data due to high energy particle (introduced in 1.7.4-1).
    • Fix time step control at negative pulse edge (introducted in 1.7.4-1).
    • If the Metis mesh partitioner failed, fall back to a simple partitioner.
  • Material Models
    • Fix CIGS bandgap data
    • Fix an instability in the mobility model of AlGaAs

Gds2mesh Modeller

  • Fix a bug in handling long-narrow 3D objects.

VisualTCAD 1.7.4-1

2012.06.03

New features. FlexLM floating license manager is used on all platforms.

Genius Device Simulator

  • Solver and Models
    • Optical anti-reflection coating at surfaces of the device.
    • Complete implementation of gate direct tunneling current.
    • Support R-C transmission line as the external circuit at electrodes.
    • Significant reduction in memory footprint.
  • General improvements
    • Specify region name with regular expressions (in PMI and MODEL commands).
    • The equation residuals are now displayed in meaningful physical units.
    • More flexible specification of linear solver and preconditioners in Half-implicit solver.
    • General convergence improvements.
    • Dedicated optimized version on RHEL6 system.
  • Bug fixes
    • Discontinuity in Hypertang mobility model.
    • Rare bug in ray-tracing.
    • Misc. bugs that affects convergence in rare cases.

GSeat Particle Simulator

  • Upgrade to Geant4.9.5
  • Fixed a geometry calculation bug in Geant4, which affects particle tracking in structures with complex geometry.
  • Improved speed of particle tracking in complex geometry.
  • Support more space-efficient HDF5 data format.

VisualTCAD/VisualFab/VisualParticle GUI

  • Support AC small-signal simulation in GUI.
    • Capacitance-Voltage sweep analysis.
    • Capacitance-Frequency sweep analysis.
  • Much improved speed in loading large device structure for visualization.
  • Improved display of device regions in visualization module.
  • Support updated GSeat(HDF5) and TIF3D v1.2 data formats.
  • Revamp wafer-state inspector and simulation manager modules and other major improvements in VisualFab.
  • Misc. bug fixes.

Gds2mesh Modeller

  • Much improved speed in generating 3D geometry objects.
  • Use unique material reference in GDML output format.
  • Support for TIF3D v1.2 data format.

VisualTCAD 1.7.3-2

2012.03.12

Improvements and bug fixes.

VisualTCAD/VisualFab/VisualParticle GUI

  • New window manager
    • Group related windows together.
    • Show/hide/close individual or group of windows.
  • Improved XY-plot module
    • Display legends on the graph.
    • Option to refresh plots when underlying data changes.
  • Bug fixes
    • When editing plot axis scale, axis properties may get applied on wrong axis.
    • Improved handling of extremely small 2D polygons.

Gds2mesh Modeller

  • Improved GDML export. Build the geometry with minimal number of faces.
  • Support custom doping profile and mesh-size control in python process rules.
  • Bug fixes
    • Fixed a buffer overflow that causes segfault.
    • Improved handling of extremely small 2D polygons.
    • Fixed polygon offsetting algorithm.

Genius Device Simulator

  • Solvers and Models
    • Support simulation in cylindrical coordinates.
    • Support custom definition of the track radius of (high-energy) particles.
    • Support distributed contact resistance.
  • General improvements
    • More efficient mesh importer for TIF data format.
    • More efficient assembly of equations at internal interfaces.
  • Bug fixes
    • Output of current at metal boundaries in half-implicit simulation.
    • Optical boundary condition settings added to .cgns files.
    • Fixed linear solver setting in AC simulation.
    • Proper warning message when
    • Optical modulation envelop is incorrect.
    • Region with no material assignment.
    • Error in reading optical spectrum data.

GSeat Particle Simulator

  • Use G4ScreenedNuclearRecoil model by default
  • Adjust the limit to the track step length, for better resolution of the final stage of ion track.

VisualTCAD 1.7.3

2012.01.01

New feature and bug fixes.

VisualTCAD/VisualFab/VisualParticle GUI

  • VisualFab is mature enough to enter the standard release.
  • Ray-tracing simulation supported in GUI
    • Setting up principal axis, light source and lenses in GUI.
    • Setting up modulation, polarization, power spectrum in GUI.
    • Self-consistent device/optics simulation supported in GUI.
  • Improved XY-plot module
    • More flexible ways to adding multiple curves to plot.
    • Axis settings saved to .plt files.
    • Extract and export data from plots.
  • Slicing function for visualizing internal variables of 3D structures.
  • General improvements
    • Use more than one processors when loading large mesh files.
    • Editing subwindow and document properties.
    • More debug/information message in log console.
    • Support Genius built with the hydra MPI process manager.
    • Expose more numerical solver options for device and circuit simulations.
  • Bug fixes
    • On Windows, loading large mesh (taking >15 seconds) used to fail.
    • In VisualParticle, setting seed number of random number generator in GUI not working.
    • In Device2D Editor, changing ruler items causes mesh to be destroyed.
    • Some default settings are not effective when VisualTCAD is used for the first time.

Genius Device Simulator

  • Stable half-implicit transient-mode solvers.

    • Proprietary correction algorithm, significantly reducing simulation error.
    • Half-implicit DDM1 and DDM2 solver are fully supported.
    • Optimized time-step control.
  • Physics and Models

    • Removed bogus surface mobility degradation at very high E-field in Lucent mobility model.
    • New material models: ZnO, CdS and CIGS.
  • General improvements:

    • Improved parallel efficiency in importing and constructing large mesh structures.
    • Expose performance profiling option to end users.
    • Preliminary support AIX operating system.
    • Upgrade to MPICH2 1.4 and MVAPICH2 1.7, switch to Hydra process manager.
    • Output gate current when applicable.
    • More warning messages when mesh quality is poor.
    • More flexible syntax for input file, list values are supported.
    • More flexible doping profile placement commands in input file.
  • Bug fixes:

    • Various import failures of mesh in DF-ISE format.
    • Buffer of some material parameters not updated after PMI commands.

GSeat Particle Simulator

  • Recover bias factor of cross-section (for neutron/proton) after reaction occurs.
  • Switch to a better random number generation and seeding.
  • Filtering by material regions in output file.
  • More particle and material information stored in output files.

Gds2mesh Modeller

  • More efficient export of model in GDML format, producing smaller-size output file.
  • Support custom-defined doping profile defined in Python script.
  • Support path objects in GDSII files.
  • GUI allows user to select top-level structures in GDSII files.
  • Improved efficiency in constructing 3D objects.
  • Fix a bug in handling 3D objects with complex shape and positions.
  • Fix a bug in doping profile calculation.

Older Releases

Year 2011 and older