【International Papers】Advanced defect spectroscopy in wide-bandgap semiconductors: review and recent results

      Researchers from the University of Padova have published a dissertation titled "Advanced defect spectroscopy in wide-bandgap semiconductors: review and recent results" in Journal of Physics D: Applied Physics.

Abstract

      The study of deep-level defects in semiconductors has always played a strategic role in the development of electronic and optoelectronic devices. Deep levels have a strong impact on many of the device properties, including efficiency, stability, and reliability, because they can drive several physical processes. Despite the advancements in crystal growth, wide- and ultrawide-bandgap semiconductors (such as gallium nitride and gallium oxide) are still strongly affected by the formation of defects that, in general, can act as carrier traps or generation-recombination centers (G-R). Conventional techniques used for deep-level analysis in silicon need to be adapted for identifying and characterizing defects in wide-bandgap materials. This topical review paper presents an overview of reviews of the theory of deep levels in semiconductors; in addition, we present a review and original results on the application, limits, and perspectives of two widely adopted common deep-level detection techniques, namely capacitance deep-level transient spectroscopy and deep-level optical spectroscopy, with specific focus on wide-bandgap semiconductors. Finally, the most common traps of GaN and β-Ga₂O₃ are reviewed.

Figure 1. Perspective power, RF, and optoelectronics applications of wide-bandgap semiconductors GaN and β-Ga₂O₃.

Figure 2. SRH model of the dynamic interaction between carriers and trap states. The four processes allowed by the model are described by the capture and emission coefficients c_n, c_p, e_n, e_p.

DOI：

doi.org/10.1088/1361-6463/ad5b6c