Multiscale investigation of nanocomposite thin films electrical properties for microelectronics applications

Context

According to the state of the art, the improvement of the dielectric materials performances for microelectronics applications and more particularly for Metal-Insulator-Metal (MIM) capacitors requires the development of nanostructured materials with increasing values of their dielectric permittivity and their breakdown field, while maintaining a low leakage current. To reach this goal 2D and 3D nanostructured materials appear promising. Indeed, the tuning of nanocomposite characteristics (nanoparticles type, shape, density…) or structuration (i.e. multilayers structure) allows to control dielectric performances. In this context, the objective of the ADN project « Advanced Dielectric Nanocomposite thin films processed by hybrid aerosol / low pressure plasma for microelectronic capacitor applications » is to design and optimize a nanostructured material (nanocomposites and / or multilayers), based on SiO₂ and TiO₂, to achieve the specific performances required for microelectronic applications.  This project will be conducted in the framework of the ADN ANR project and is based on a collaboration between l’Institut des Matériaux de Nantes (IMN), having an expertise in the domain of nanocomposite thin films elaboration (thickness < 50 nm), and the Laboratoire Plasma et Conversion d’Energie (Laplace), having an expertise on characterization of the dielectric properties of insulating materials and on plasma physics.

One of the objectives of the project is consequently to understand and to model the impact of the nanostructuration of the materials on the overall dielectric properties, in order to propose new nanostructured materials for microelectronics applications, using reverse engineering. 

PhD’s objectives

Nanocomposite thin films will be elaborated and structurally characterized at IMN. The main objectives of the PhD work is to identify the influence of nanostructuration (nanoparticles, interfaces properties, nanoparticles dispersion…) on dielectric properties of nanocomposite/nanostructured thin dielectric layers.

To reach this goal nanocomposites and multilayers samples will be characterized and modelled. The main objectives of the Phd are the following:

• Nanoscale electrical characterization of the different materials elaborated at IMN, by atomic force microscopy (AFM): current by conductive AFM (CAFM), dielectric permittivity by Electrostatic Force Microscopy (EFM) and charges by Kelvin Probe Force Microscopy (KPFM)
• Macroscale electrical characterization by current and capacitance versus voltage characteristics and dielectric spectroscopy
• Finite element modelling of electrical properties of nanocomposites and multilayers thin film to understand the influence of nanostructuration (nanoparticles vs layer) and interfaces on the overall macroscopic properties 

Le Laboratoire Plasma et Conversion d’Energie est une Unité Mixte de Recherche du Centre National de la Recherche Scientifique (CNRS), de l’Institut National Polytechnique de Toulouse (INPT) et de l’Université Toulouse 3-Paul Sabatier (UPS).

Les travaux de thèse seront réalisés au sein de l'équipe Diélectrique Solide et Fiabilité (DSF). Les activités de l’équipe concernent en premier lieu la fiabilité des systèmes isolés. Les travaux ont pour objectif la compréhension des mécanismes de génération et de transport de charges dans les isolants, ainsi que l’identification des processus conduisant au vieillissement et à la rupture de matériaux compte tenu des contraintes fonctionnelles rencontrées dans les dispositifs. Pour cela, des techniques de caractérisation originales sont mises en œuvre et l’on s’appuie sur une simulation numérique des phénomènes de transport.

Master degree or engineer degree in materials, electronics, microelectronic with skills in electrical characterization and/or modeling. Strong interest in experiment and modelling.