Speaker
Description
The manipulation and observation of charge carrier distributions at the interfaces of semiconductor device structures is a fundamental problem in semiconductor physics. Standard electrical characterization techniques, such as deep level transient spectroscopy (DLTS) or capacitance-voltage (CV) measurements, have limited depth resolution and are unsuitable to probe the nanometer scale regions at semiconductor interfaces, where electron and hole transport is directly influenced by changes in applied bias/band bending. We have recently developed an extension to the LE-$\mu$SR setup at PSI that allows us to apply an external electric field across a thin-film sample, while the sample can be floated to ±10 kV to adjust the implantation energy of the muons for performing depths scans. With this “Electric-field-LE-$\mu$SR” (EF-LEM), we were able to observe for the first time the change in electron concentration in Si/SiO$_2$ and 4H-SiC/SiO$_2$ structures with nanometer depth resolution, which can be controlled by the EF. We use the muonium state in the semiconductors as a sensitive probe for the presence of free charge carriers and extract their depth distribution [1].
[1] M. Martins et al., arXiv:2405.18211
| thomas.prokscha@psi.ch | |
| Funding Agency | Swiss National Science Foundation (SNSF), grant number 192218 |
