Third party funded individual grant
Start date : 01.01.2021
End date : 31.12.2023
Today, 4H-SiC is the most prominent wide bandgap semiconductor material with respect to commercially available power semiconductor devices. Very recently, 4H-SiC has also become very attractive for quantum devices. For both applications, defects play a major role – either being detrimental to power device performance (e.g., compensation of p-type doping, reduction of charge carrier mobility) or being essential for quantum effects (e.g., color centers).
Focused ion beam systems (FIB) allow localized implantation of ions in a target material which in turn very locally generates defects in the material. Besides, the relatively flexible choice of implantation energy and dose widens the level of defect generation as well as the actual defect depth profile. Recently, new kind of ion sources for e.g. Helium (i.e. Helium Ion Microscope, HIM), Neon, Xenon but also B, Au etc. have been developed. In comparison with the widely adopted Gallium FIBs, the new ion sources cannot only show unique advantages like easily realizable <5nm structure fabrication and implantation by HIM, relatively large machining ability by Xenon plasma source, but also the implantation of functional ion species such as B for local doping of 4H-SiC. Besides, many new phenomena appear like helium bubble formation, severe swelling of affected target regions due to such new ion species.
This SGC Mobility Programme aims to deepen the knowledge and understanding of ion implantation induced defects in 4H-SiC by focusing on specific ion-sample interaction mechanisms in 4H-SiC, defect generation by FIB nanofabrication techniques, and defect characterization. This includes: 1) Density Functional Theory (DFT) calculation of generated point defects in 4H-SiC; Molecular Dynamics (MD) simulation of He implanted in 4H-SiC with annealing and the defects analysis. 2) Investigation of the influence of the FIB ion source on the generated defects, including the formation of helium bubbles, swelling, local strain/stress, etc. 3) Characterization of FIB induced defects by characterization techniques, including, 3D Raman/Photoluminescence spectroscopy profiling, Optically Detected Magnetic Resonance (ODMR), Electron Paramagnetic Resonance (EPR), TOF-SIMS, etc.