Defence in the field of Micro and Nanosciences M. Sc. (Tech.) Alessandro Inglese
The title of thesis is “On the light-activation of copper impurities in crystalline silicon: root cause analysis and applications for fast high-resolution imaging”
Silicon is the workhorse material of a variety of semiconductor-based devices. While in integrated circuits extensive research on this material has resulted in ever-increasing levels of miniaturization, in photovoltaic applications continuous advances in crystallization processes have resulted in efficient and cost-effective solar cells. A common requirement among all applications of silicon is the de-mand for increasingly stringent levels of purity and crystal perfection.
This dissertation focuses on one of the most insidious metallic contaminants in silicon materials, i.e. copper, and presents a comprehensive study of a parasitic effect caused by such impurity, which is often referred to as light-induced degra-dation. Since this phenomenon is triggered by exposure to visible light, such par-asitic effect is a particular issue in photovoltaic devices and light detectors.
This dissertation primarily aims to shed light on the root cause behind the copper-related light-induced degradation. On the base of the new knowledge acquired through these fundamental studies, this thesis work proposes an advanced algo-rithm for quantitatively estimating the impurity density from customary characteri-zation measurements. As a result, copper contamination in silicon materials can be monitored and quantified during all steps of device fabrication, such that con-taminated materials can be identified and excluded from manufacturing lines.
Opponent: Dr. Ronald A. Sinton, Sinton Consulting Inc., United States
Supervisor: Professor Hele Savin, Aalto University School of Electrical Engineering, Department of Electronics and Nanoengineering.
Venue: Aalto University School of Electrical Engineering, Maarintie 8, Hall AS1