Princeton University

School of Engineering & Applied Science

Investigations on some side effects and defect formation during plasma etching of nanostructures using III-V semiconductors

Professor Jean-Pierre Landesman, Physics Institute, University of Rennes, France
Equad B418
Tuesday, January 16, 2018 - 11:00am

Reactive ion etching, based on the controlled interaction of the semiconductor surface with highly reactive plasmas, is one of the most important building blocks in nanotechnology platforms nowadays. This technique was introduced in the fabrication processes several decades ago, however it relies on a complex interaction between the surface and the plasma phase. There are still some aspects of this interaction which require investigations, especially as the tools become more powerful, for example on the route towards faster etching processes with better control on the critical dimensions. In this presentation, I will focus on the issue of the damage that can be introduced in the etched materials due to the presence of energetic ions in the plasma for example. I will discuss some of the “old” work that was undertaken by pioneering groups to investigate associated defect formation, especially in III-V materials. I will then show some more recent results that build on these ideas, mainly using spectroscopic techniques with high spatial resolution to investigate defect formation in quantum well structures on InP, after exposure to different etching plasmas. I will also address the question of mechanical stress that can appear in some structures after plasma etching, for example in the case of InP etched with chlorine-based chemistries.