Utilization of photon emission microscopy in determining drain junction property of submicron NMOSFETs

Abstract

Photons are emitted from silicon MOSFETs and it has been known that they are closely related to the impact ionization which is caused mainly by hot carriers. In this study, we have used photon emission microscope to analyze drain junction quality, especially silicide-silicon interface in the N+ drain region. We will intend to show that a device with high drain sheet resistance emits more photons than others even though the devices have identical hot carrier degradation characteristics. Furthermore, we found that the photon intensity profile can be used to check the quality of silicide-silicon interface. We confirmed the interface degradation of silicide thinning caused by agglomeration by taking TEM pictures of devices with unusually noisy photon emission profiles.