NIFA Iliass

PhD Defense of NIFA Iliass

« Characterization and modelling of 2D electron gas of MISHEMTs devices on GaN »
Friday, march 2nd, 2018 at 10:30

This thesis aims at studying the electrical characterization and modelling of two-
dimensional (2D) electron gas in MOS-HEMT devices based on the hetero-junction
AlGaN/AlN/GaN. These devices are very promising candidates for power electronics
applications. This research work provides the production team with detailed data on
phenomena affecting GaN material. The goal is to understand precisely how 2D electron gas works and evaluate its electronic transport properties. A new methodology has been developed to identify residual doping of the GaN layer. This method was developed in order to answer a real need to know this doping to determine the quality of the epitaxial GaN layer.
The second research priority was to provide reliable measurement techniques and modelling of the transport properties of 2D electron gas. Within this framework, the split-CV and Hall effect measurements were carried out by providing for each of them a suitable experimental protocol, with an innovative set-up for Hall effect measurements. In addition, this experimental work was supported by modelling the transport properties of 2DEG based on Kubo-Greenwood's formalism. Finally, a more general aspect aimed at an in-depth understanding of the electrostatic stacking of the GaN-MOS-HEMT gate. It is based on C-V electrical characterization, modelling and parameter extraction. This developed model highlights the impact of polarization surface charges and defects on the threshold voltage of MOS-HEMT. This model also contributed to the estimation of the value of deformation in epitaxial GaN layers on a Silicon substrate.
Membres du jury :
  • Edwige BANO - Supervisor
  • Nathalie LABAT- Reviewer
  • Jean-Guy TARTARIN - Reviewer
  • Karim BOUTROS - Examiner
  • Dominique PLANSON - Examiner


Thesis prepared in the laboratory : CEA -CEA-LETI, supervised by  BANO Edwige and GHIBAUDO Gérard Cosupervisor.
Date infos
Defense of the doctoral thesis of  NIFA Iliass, for the University Grenoble Alpes, speciality  "NANO ELECTRONIC & NANO TECHNOLOGIES ", entitled:
Location infos
Amphi  Z108 (Bâtiment Z 1st floor) - Phelma/Minatec
3 rue parvis Louis Néel
38016 Grenoble cedex1