Developement of a DLTS bench for semiconductor defects characterization.

Abstract :
Deep level transient spectroscopy (DLTS) is a technique used to study electrically active defects in semiconductor materials. It involves the measurement of the depletion capacitance response time after a voltage pulse on a large temperature range. Typically, those measurements are realized by black-box systems (such as Phystech) on cryostats with temperatures varying from liquid helium to ambient temperature. While those systems are sufficient to study small bandgap semiconductor such as Si, it is not sufficient for large bandgap materials like SiC or GaN. Moreover, they lack flexibility when we want to define very specific tests conditions. For that reason, we developed a DLTS system based on the MFIA impedance analyzer using Python language on a compact station from Microworld where the temperature can increase up to 600°C (873K). This presentation is separated in two parts. In the first one, we will present a trap study on 4H-SiC diodes realized with a Phystech DLTS system. In the second part, we will present the developed DLTS system and makes some comparison with the Phystech system.