III-V materials etch process development for power device application
Published : 15 July 2019
Formation of the two-dimensional electron gas (2DEG) in AlGaN/GaN heterostructrures is the key-point for successful development of GaN-based power-electronics such as High Electron Mobility Transistors (HEMT) and diodes. Plasma-etching steps are considered as critical in fabrication for such devices.
The aim of this thesis is to understand the etch mechanism of III-V materials using traditional etch chemistry and its impact on the film damage.
An atomic layer etching (ALE) process developed at LETI will also be studied. This ALE process consists in etching the III-V material with cyclic steps. The first step is a chlorine based process to chemically modified the film at its surface, then an argon plasma is performed to selectively remove the modified layer.
The goal of the thesis is to develop and characterize these plasma etch processes. This understanding of plasma surface interaction function of the etch chemistry will be studied on CEA-LETI etch tools using complementary useful characterization techniques like XPS, Tof SIMS, TEM-EELS…