Charge-induced voltage alteration (CIVA) is a technique which uses a scanning electron microscope to locate open conductors on CMOS integrated circuits. This technique is used in

semiconductor A semiconductor is a material which has an electrical conductivity value falling between that of a conductor, such as copper, and an insulator, such as glass. Its resistivity falls as its temperature rises; metals behave in the opposite way. ...

failure analysis Failure analysis is the process of collecting and analyzing data to determine the cause of a failure, often with the goal of determining corrective actions or liability. According to Bloch and Geitner, ”machinery failures reveal a reaction chain o ...

Theory of operation

The scanning of an

electron beam Cathode rays or electron beam (e-beam) are streams of electrons observed in discharge tubes. If an evacuated glass tube is equipped with two electrodes and a voltage is applied, glass behind the positive electrode is observed to glow, due to ele ...

across the surface of the device may result in additional

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buildup on conductors which are disconnected from the remainder of the circuit (floating conductors). If a CMOS device is under active bias, the presence of open conductors may not prevent the circuit from operating at low clock frequencies as the result of

quantum tunneling In physics, a quantum (plural quanta) is the minimum amount of any physical entity (physical property) involved in an interaction. The fundamental notion that a physical property can be "quantized" is referred to as "the hypothesis of quantizat ...

effects. By injecting charge into

floating conductor Floating may refer to: * a type of dental work performed on horse teeth * use of an isolation tank * the guitar-playing technique where chords are sustained rather than scratched * ''Floating'' (play), by Hugh Hughes * Floating (psychological ph ...

s that are operating in this tunneling mode, it is possible to produce additional loading which can be detected by monitoring the power supply

current Currents, Current or The Current may refer to: Science and technology * Current (fluid), the flow of a liquid or a gas ** Air current, a flow of air ** Ocean current, a current in the ocean *** Rip current, a kind of water current ** Current (stre ...

. These changes in supply current may be associated with the visual image of the device at the coordinates at which the change was detected. The result is a scanning electron microscope image which has an overlay of the floating conductors superimposed on it.

References

* {{cite conference, last=Cole, first=E., title=Beam-Based Defect Localization Methods , book-title=Microelectronics Failure Analysis , pages= 408–411 , year=2004 , publisher=ASM International , isbn= 0-87170-804-3 Semiconductor analysis