Meticulous system calibration as a key for extracting correct photon emission spectra

Photon Emission (PE) spectra have been investigated for decades in order to extract important data of device failures or characteristic parameters. InGaAs detectors are more problematic than Si detectors because of their more pronounced noise behaviour. Many published results of spectral analysis performed with InGaAs detectors have not been fully conclusive. With a principal approach as to which spectra can be expected from digital ICs in PE, the shape of the measured spectra did not always correspond to these fundamental principles. This paper shows that a meticulous calibration of a spectral photon emission microscopy (SPEM) setup is the key to extracted PE spectra that correspond to the theoretical basics. Furthermore, a concept for the implementation of a thorough calibration procedure is given and several errors that may occur during this procedure as well as their influence on spectral analyses are discussed. Finally, the parameter electron temperature of the field effect transistor (FET) can be successfully extracted from InGaAs based spectra.