MDP and MD-PICTS measurements on SiC and GaN

In recent years the quality of SiC and GaN materials has improved profoundly, hence it is becoming more and more a suitable competitor to Si for e.g. high power devices. Since it is a wide band gap semiconductor SiC has a number of advantages when compared to silicon. In order to manufacturing SiC devices with maximum yield a high resolution material quality characterization is needed, together with a method for the investigation of defects in SiC to further improve the quality.

The two contactless and destruction free methods Microwave Detected Photoconductivity (MDP) and photo induced current transient spectroscopy (MD-PICTS) are ideal methods for material quality and defect characterization. The MDPmap combined with a UV-Laser (355 nm) is the ideal tool for the spatial investigation of inhomogeneity in the minority carrier lifetime of SiC.

MD-PICTS measurements enable the temperature dependent investigation of the photoconductivity transient allowing the determination of the defect activation energy and capture cross sections.

 

 

 

Fig. 1: Minority carrier lifetime map of a 2 x2 cm 3C-SiC sample with an average lifetime of 5.92 µs
Fig. 2: Typical signals of GaN with persistent photoconductivity

For more information please read:

[1] B. Berger, N. Schüler, S. Anger, B. Gruendig-Wendrock, J. R. Niklas, K. Dornich, physica status solidi A, 1-8