The VWF is powerful software, capable of performing Design of Experiments (DOE) and Optimization Experiments. Split-lots can be used to perform various pre-defined analysis methods. The Software allows split parameters to be defined for any of the Silvaco process, device and circuit simulators. All simulations carried out in parallel either on a cluster of workstations or on a single SMP machine. VWF comes as a comprehensive and powerful modern GUI application, that also allows examination of experimental results.

Key Features:

• VWF can represent an entire flow from process simulation to spice circuit performance or just part of the flow.
• Flexible system allows experiments to be defined where any mix of; masks, process parameters, device parameters, circuit parameters or tuning coefficients can be defined as input variables
• Experiments can be defined by varying the input parameters automatically via an experimental design such as Box Behnken or defined manually
• Outputs responses of interest can be measured from the entire flow including; process characteristics such as oxide thickness, device characteristics such as pvt or circuit characteristics such as rise time
• Each experimental variation can be run on a network of hosts to speed simulation time
• Response models can be generated over the experimental spread and then input parameters can be rubber banded to see the effect on output responses
• Full worksheet of input, measured output responses and RSM’s can be exported to SPAYN for additional statistical analysis or TonyPlot Production mode for additional graphical analysis
  

Database Manager

• All process, device decks and results are stored inside the database
• Archive area of database designed to be composed of process or device library objects
• Library objects include process operations, parameter device tests, IC layouts, IC layouts cutlines
• Design flow manager allows drag and drop of library objects into a new process flow
• Design flow manager allows easy creation of new process flows from an already characterized process library of individual process steps
  

Database Manager the archive allows particular process steps and electrical tests to be saved as individual operations in the database.

Design Flow Manager builds new process flows and device tests by drag and drop from the database archive.

Split Lot Manger

• Allows selection of process steps where a design split will occur
• Design split points may be layouts, implant parameters, diffusion parameters
• Resultant split tree is visually displayed
• Each leaf of the design tree may be selected to provide information on the simulation runtime output or to plot the current structure for that particular process flow
• Allows user to submit for simulation a single leaf, groups of leaves or D-optimal queueing

Split Lot Manager shows the split lot tree where each leaf can be chosen for analysis.

Experimental Design Generator

• Shows available process steps that may be selected to perform a set of split lots on
• Each process step may be chosen independently and a DOE chosen for it
• The design of experiment (DOE) choices include
  • full factorial and partial factorial orthogonal designs
  • box Benkhen, Face Centered Cubic and Circumscribed Composite designs
  • linear random and latin hypercube designs
  • Gaussian random design
• Sensitivity analysis where each selected variable is varied +/- a defined percentage
• After selecting the range for the DOE the design generator will fill in the split lot tree with all the selected variations

Experimental Design Generator - The DOE for each variable is chosen from the pull down menu.

Network Job Controller

• Controls distribution of simulation jobs across the network
• Displays all machines on the network that have the VWF database installed
• Allows new machines to be added
• Shows a complete list of all jobs in the simulation queue for all displayed machines
• Shows the state of each machine to be controlled
• Machine status can be
  • currently simulating a job
  • waiting for a job to be sent to it
  • on timeout; only allows jobs to be run between certain defined hours
  • paused indefinitely
• Allows selected jobs to be canceled from the queue
• Controls number of jobs sent to a single machine at any one time (for multi-cpu machines)

Network Job Controller distributes and controls job submission to machines across a network.

Interactive Worksheet Editor

• Displays in the worksheet the selected variations in the process parameters as well as any extracted results during the simulation such as Vt, sheet rho, oxide thickness etc.
• Additional splits may be added into the worksheet for simulation
• Selection of splits may be enabled or disabled before being simulated
• Results can be selected to be sent to the result analyzer or to be exported to SPAYN for further statistical analysis
  

Interactive Worksheet Editor displays all process splits and any extracted results.

Result Analyzer

• RSM model generation
• Interactive model visualization
• Sensitivity analysis
• Process synthesis
• Multi-variant calibration
  

Result Analyzer From the worksheet the data can be sent to the analyzer for plotting.

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