Time-resolved photon emission (TRPE) is used to measure timing waveforms on semiconductor devices. TRPE measurements are performed on the back side of the semiconductor device. The substrate of the device-under-test (DUT) must first be thinned mechanically. The device is mounted on a movable X-Y stage in an enclosure which shields it from all sources of light. The DUT is connected to an active electrical stimulus. The stimulus pattern is continuously looped and a trigger signal is sent to the TRPE instrument in order to tell it when the pattern repeats. A TRPE prober operates in a manner similar to a sampling oscilloscope, and is used to perform semiconductor

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

As the electrical stimulus pattern is repetitively applied to the DUT, internal transistors switch on and off. As pMOS and nMOS transistors switch on or off, they emit

photon A photon () is an elementary particle that is a quantum of the electromagnetic field, including electromagnetic radiation such as light and radio waves, and the force carrier for the electromagnetic force. Photons are Massless particle, massless ...

s. These photons emissions are recorded by a sensitive photon detector. By counting the number of photons emitted for a specific transistor across a period of time, a photon

histogram A histogram is an approximate representation of the distribution of numerical data. The term was first introduced by Karl Pearson. To construct a histogram, the first step is to " bin" (or " bucket") the range of values—that is, divide the ent ...

may be constructed. The photon histogram records an increase in photon emissions during times that the transistor switches on or off. By detecting the combined photon emissions of pairs p- and n-channel transistors contained in

logic gates A logic gate is an idealized or physical device implementing a Boolean function, a logical operation performed on one or more binary inputs that produces a single binary output. Depending on the context, the term may refer to an ideal logic gate ...

, it is possible to use the resulting histogram to determine the locations in time of the rising and falling edges of the signal at that node. The waveform produced is not representative of a true voltage waveform, but more accurately represents the derivative of the waveform, with photon spikes being seen only at rising or falling edges.

References

* Semiconductor analysis {{tech-stub