Figure 4.14: Gate Oxide Short
Another fault type that Carafe is capable of extracting is Gate Oxide Short (GOS) faults. Figure 4.14 shows a cross section of a circuit showing the possible GOS faults that Carafe will find. These faults are modeled like Bridges by adding extra transistors in the netlist for testing and simulations. Carafe reports these faults as shorts between the diffusion and polysilicon regions of the transistor. The weight of the GOS for each transistor type is listed in the gos section of the fabrication file.
GOS fault extraction can be enabled by pressing the button label "Gate Oxide" in the Bridges section of the Extract window. GOS faults are output the same way that bridge faults are, i.e. they appear in the .pro file.