Promotionsvortrag Physik: „Electrical characterization of point defects in silicon high voltage diodes“

Ankündigung des Promotionsvortrags von: Frau Lena Bergmann

Power semiconductors are essential for building efficient power systems and are part of applica-tions such as drives and traction applications. High-voltage silicon (Si) diodes are key compo-nents, and their efficiency can be enhanced by introducing point defects. Substitutional platinum (Pt), for instance, is a powerful tool for minority carrier lifetime control, which reduces switching losses and increases diode efficiency. For device optimization, a comprehensive understanding of how different process parameters affect the Pt concentration and distribution is required, ne-cessitating advanced methods for characterizing point defects across the entire substrate of power semiconductors.

To address this, a newly developed high-voltage Current Transient Spectroscopy (HV-IDLTS) setup was introduced. This technique enables precise, non-destructive defect characterization and has been employed to investigate the effects of damage implantations on the distribution of Pt and platinum-hydrogen (PtH) defects in 1.2kV Si diodes.

In industrially fabricated HV semiconductors, defect concentrations can exceed the doping con-centration, where the traditional I-DLTS model is no longer valid. To overcome this, a new I-DLTS model has been developed, accounting for trap charges and a time-dependent Fermi energy. Combined with the HV-IDLTS setup, this approach enables a precise analysis of point defects in power semiconductors, paving the way for improved optimization and higher device efficiency.

(Vortrag auf Englisch)

Dem Vortrag schließt sich eine Diskussion von 15 Minuten an. Vortrag und Diskussion sind öffentlich. Diesen Verfahrensteilen folgt ein nicht öffentliches Rigorosum von 45 Minuten.