Aidan Taylor

Understanding the distribution of crystal defects is an important topic for semiconductor materials. This is particularly challenging for gallium nitride on silicon (GaN-on-Si) as the defects have a density of ~5×10^9 cm-3. Understanding – and ultimately monitoring – crystal defects at this density is an unsolved problem.
Transmission electron microscopy (TEM) is the gold standard for understanding crystal defects, and it has a body of understanding going back 60+ years, but the equipment expense and low sample throughput make it unattractive for any statistical studies of crystal defects. More recently, scanning electron microscopy (SEM) has shown promise for quantitative defect measurements in GaN, using electron channelling contrast imaging (ECCI).
In this work, we have performed a detailed study of the same 132 dislocations in a GaN sample with both SEM and TEM. The dislocation type (a-type, c-type, a+c-type) was determined with both methods. Only three measurements differed between the two methods. This work paves the way for ECCI in SEM to be ramped-up as a monitoring tool for dislocation type in GaN, at least for epitaxy development.

Aidan wrote his PhD at the University of Leoben, Austria, on the subject of metal-ceramic interfaces. He then studied thin film photovoltaic materials and thin, hard, coatings as a postdoc in Durham, England, and at EMPA, Switzerland, before managing the electron microscopy core facility at the University of California Santa Barbara.
Now at Infineon Technologies Austria, Aidan works in failure analysis where he is specialises in all forms of electron and ion microscopy with a particular focus on Gallium Nitride technologies. He also teaches failure analysis methods at the Carinthian University of Applied Sciences.