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6.4 Robust Operation and Error Handling

To achieve smooth and stable execution of large-scale experiments and complex analysis tasks, fault-tolerance is a top priority for a simulation environment. The effect of an error, e.g., a failing system call or a numerical error, has to be limited to the affected experiment, with all other tasks in progress remaining undisturbedgif.

For the integration of external tools, the main concern lies on the detection of errors. To this end, several standard procedures are available in the VISTA/SFC environment to check the return code of system calls, to verify the existence of output files, and to examine the data generated. For instance, generated PIF files are automatically checked for containing the desired dopant distributions or geometry data. These procedures are encapsulated in a class of system tool objects automatically employed on every system call issued by the framework. If necessary, additional error handling routines can be defined for each system executable as well as for each application.

Robust operation is a an indispensable prerequisite for taking full advantage of CAD support for technology development and analysis. The reluctance usually encountered when proposing to perform several hundred (or thousand) process flow simulation runs, each involving a number of process steps and leading to the invocation of a variety of simulation tools, is very much based on the fact that in most cases, human interaction is required at many stages of the simulation, making large experiments cumbersome and time-consuminggif. Therefore, response-surface modeling plays a very important role in technology design and optimization, as it allows to reduce the numbers of actually simulated design space points [AAYtex2html_wrap870088] [MOAtex2html_wrap870091] [CBKtex2html_wrap870093] [KKW93] [BM94] [GW94] [STAtex2html_wrap870095] [SLW96]; in Chapter 8, the integration of RSM techniques is treated in more detail.





Christoph Pichler
Thu Mar 13 14:30:47 MET 1997