The attached figure shows two distinctly different device technologies---silicon MOSFET and Gallium Arsenide MESFET devices---created as "virtual devices" using 3D computational solid geometry. Base on these structures, "virtual instruments" are used to simulate the device behavior and demonstrate the predicted performance in the form of curves that the real devices will exhibit when fabricated and measured in the lab. The upper left curve shows the electrostatic discharge (ESD) breakdown of a MOSFET protection device. Such simulations are invaluable in predicting reliability of ICs.
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