"High-Resolution Quantitative Cathodoluminescence (CL) for Defect Metrology in Semiconductors"

Samuel Sonderegger, CEO & Co-Founder of Attolight AG

April 7th (Friday), 8:30am
Engineering Science Building (ESB), Rm 2001

High spatial resolution spectroscopic information may be acquired by using an electron beam in a modern scanning electron microscope (SEM), exploiting a phenomenon called cathodoluminescence (CL). CL can be used to perform non-destructive analysis of a broad range of materials comprising insulators, semiconductors and metals. This approach offers several advantages over usual optical spectroscopy techniques. The multimode imaging capabilities of the SEM enable the correlation of optical properties (via CL) with surface morphology (secondary electron – SE – mode) at the nanometer scale. In semiconductors and insulators, the CL spectrum gives local information on the electronic bandgap and defect states. In metals and nanostructured materials, CL is sensitive to the local density of optical states (LDOS) and allows direct probing of nanophotonic devices. We will show how high resolution hyperspectral CL microscopy is routinely used to perform defect and homogeneity metrology as well as failure analysis in semiconducting materials. Examples on optoelectronic and solar cells devices will be highlighted. In addition, we will give examples of CL imaging of nanophotonic structures used as single photon sources, or for lasing and sensing applications. Finally, we will show how the introduction of pulsed electron excitation and time resolved detection of the CL signal (TRCL) allows carrier dynamic probing at the nanoscale.

About Samuel Sonderegger:

Attolight AG was founded in 2008 by Samuel Sonderegger and Jean Berney who manage the company today. The combined knowledge of scanning electron microscopy and ultrafast spectroscopy from the Laboratory of Quantum Optics and Electronics of EPFL was transferred to the company that turned the unique technology into a new product line. Attolight is supported by a group of high-level private investors.

Hosted by: Professor John Bowers