VWF Production Tools Bring VWF Capability Closer To Manufacturing Reality

The complexity and the long run times of modern TCAD have prevented mainstream semiconductor engineering groups from using it extensively. A new set of tools called the Virtual Wafer Fab (VWF) Production Tools allow a wider range of users, including production engineers, to gain easy access to the automatically generated results of the VWF Automation Tools.

The VWF Automation Tools are designed to automate the job of generating Response Surface Models from simulation based split lot experiments. The VWF Production Tools may be run in a completely standalone environment, decoupled from both process and device simulation. A highly simplified user interface allows the study of the effects of the process flow on almost any design parameter.

Easy to use sliders representing the values of processing parameters are interactively moved causing the resultant design parameters to move graphically in real time.

Figure 1 indicates the usage of the Production Tools, remote from the Central VWF database system. Response Surface Models (RSM) are generated by TCAD users with the VWF Automation Tools. These RSM's are calibrated and then sent to other engineering groups for use with the Production Tools. The Production Tools may be run on either UNIX workstation platforms or on a PC running MS Windows.


Figure 1. Typical configuration of VWF usage.


Yield Analysis engineers may study the effect of either a single processing parameter, or a number of processing parameters upon the yield distribution at end of line. Questions such as, "How important is the misalignment of this layer, to the yield of the parametric parameters?" may be addressed accurately and quantitatively.


Failure analysis engineers, trying to understand a particular set of failed device parametric parameters could use the Production Tools' Failure Analysis module to show a relative probability distribution of likely causes of failure.


Analog design engineers are finally able to study technology effects on SPICE model parameters, including BSIM3. This tool represents a breakthrough in terms of communicating the effects of technology processing to design engineers.


Figure 2. VWF Production Tools allow new users to make use of previously
generated TCAD results. In this example, n and p channel
threshold voltages may be quickly and easily balanced in seconds.


Figure 3. 2D and 3D contour plots may be moved interactively
under slider control, to modify device parameters.