Dielectric materials are technologically important in the semiconductor industry. They are used as gate oxides in metal oxide semiconductor field effect (MOSFET) transistors. Silicon dioxide and silicon nitride are studied extensively using cathodoluminescence (CL) to characterize point defect clusters' structure and electronic properties.
In more recent years, CL continues to play an important role as high-κ dielectric materials replace SiO2. For example, depth-resolved CL spectroscopy can detect and locate defects and interfacial states within ultra-thin (<4 nm) gate oxides. In hafnium oxide, CL techniques detect the presence of several oxygen vacancy defects, their evolution during thermal processing, and the formation of hafnium silicates (HfSiO4) at the silicon-oxide interface. In LaLuO3, defects produced by LaLuO3–Si interdiffusion have been detected, and these defects have been suppressedby monolayer thick Al2O3 interlayers.