EOFM for contactless parameter extraction of low k dielectric MIS structures

This paper investigates electro-optical frequency mapping (EOFM) characteristics of metal insulator semiconductor (MIS) capacitor test structures. The EOFM characteristic describes the EOFM signal intensity dependence to the device under test (DUT) input signal amplitude. We can monitor the gradual increase of charge per voltage in accumulation and in strong inversion. We show that the device parameters flat band voltage and the threshold voltage can be extracted from a series of EOFM measurements. This parameter extraction is linked to a low k dielectric degradation experiment. Changing of the extracted parameters during a degradation process allows contactless monitoring of the device properties and their degradation under electrical stress.