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