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The Atom Probe Tomography (APT), the laboratory's flagship technique, enables the 3D reconstruction of the chemical distribution of a nano-object, with spatial resolution close to the atomic scale, using field evaporation of ions from the surface. In laser-assisted APT, commonly used to study metals, insulators and semiconductors, evaporation is triggered by an ultrafast laser pulse in the near ultraviolet (UV) range [1-2].

Teeth are particularly fascinating due to their remarkable properties and essential role in mastication. While most dental research focuses primarily on human or mammalian teeth, the diversity of dental tissues in animals provides valuable insights for biomaterials, biomineralization, and bio-inspired designs.

Project description

The objective of this thesis is to study trap phenomena in the latest generations of Gallium Nitride (GaN)-based High Electron Mobility Transistors (HEMTs). Various methods for characterizing trap behavior in GaN HEMTs exist, such as Deep Level Transient Spectroscopy (DLTS) for capacitance and current (C-DLTS and I-DLTS), Athermal Direct Current Transient Spectroscopy (A-DCTS), Deep Level Optical Spectroscopy (DLOS), Gate-Lag (GL) and Drain-Lag (DL) transient measurements, the study of transconductance frequency dispersion, S-parameter measurements, and low-frequency noise measurements.