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Offers : 34

Extreme conditions instrumentation and studies

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Start date : 1 January 2019

offer n° PsD-DRF-18-0100

Combining extreme conditions of low temperature, high pressure, and magnetic field is crucial for numerous systems where the coupling between the electronic, magnetic and lattice degrees of freedom gives rise to fascinating properties, both from a fundamental and applications oriented point of view. Studies under pressure and static magnetic field are limited by the maximum fields available (about 35T in France today). Pulsed magnets can reach much higher fields, the world record is around 100T, but measurements under pressure in pulsed fields are a big challenge, and so far are not routinely available. In collaboration with the CNRS LNCMI Toulouse. We have explored a novel approach, and a successful prototype has been built and used to measure magnetoresistance in pulsed fields up to 60 T, pressure up to 5 GPa, and temperatures down to 1.5 K. This prototype will allow the candidate to quickly learn the technique and perform tests and measurements. A large part of the task will be to implement and test improvements, with the aim to achieve lower temperatures, higher pressures, and higher fields, but also create a reliable and easy to use device. In collaboration with the CEA/DAM/DIF Laboratory, we will also test a miniature diamond anvil cell in pulsed field, opening the prospects of much higher pressures.

These novel measurements will be valuable in a wide range of domains. From the outset we will combine tests of the new developments with measurements on samples of physical interest. The choice of which studies to undertake will be made with the candidate: Topics that are of interest include magnetism of strongly correlated systems, high-Tc superconductivity, correlation driven insulators (Mott or Kondo), and topological systems.

  • Keywords : Engineering science, Instrumentation, Solid state physics, surfaces and interfaces, INAC, PHELIQS
  • Laboratory : INAC / PHELIQS
  • CEA code : PsD-DRF-18-0100
  • Contact : daniel.braithwaite@cea.fr

High resolution investigation of CdZnTe single crystal and HgCdTe/CdZnTe thin films at ESRF

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Start date : 1 August 2018

offer n° PsD-DRT-18-0090

CEA-Leti has a long experience and a strong expertise in the crystal growth of HgCdTe based compounds for infrared applications with performances directly related to material quality. In particular, crystal defects may lead to detector failure through current leakage in the infrared diode characteristics. This postdoc position is open in the general context of understanding the mechanisms of defect formation and propagation in these materials. More specifically, this postdoc is dedicated to the high-resolution investigation of these defects using synchrotron radiation. A series of rocking curve imaging (RCI) experiment is ongoing and will continue through 2018 and first images already reveal a variety of crystal defect arrangement within CdZnTe substrates. It is the aim of this postdoc to carefully analyze the existing data in order to extract quantitative information that could be directly used to characterize the material quality but most importantly to correlate the nature of the defects to the history of bulk crystal growth. Results would also be used to guide the team for the choice of samples for next RCI runs but also should lead to new experiment proposal within ESRF environment or possibly using other synchrotron facilities.

  • Keywords : Radiation-matter interactions, Solid state physics, surfaces and interfaces, DOPT, Leti
  • Laboratory : DOPT / Leti
  • CEA code : PsD-DRT-18-0090
  • Contact : philippe.ballet@cea.fr

compact models development for Qbit

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Start date : 1 August 2018

offer n° PsD-DRT-18-0056

The Compact / SPICE model is the link between the development of technological bricks and circuit design. The model purpose is to accurately reproduce the experimental characteristics essential to digital, analog and mixed circuit design. Thus, the extraction parameters corresponding to the electrical characterization.

The main challenge is to be able to describe the quantum behavior of this architecture. It will also be necessary to study if this behavior must be described via the physical quantities (eg electronic spin, energy level …) or by logical quantities (quantum state, matrix of transformation, …). It will also be necessary to take into account the compatibility between the mathematical formalism and the standard tools of compact modeling (through Verilog-A description).

In view of the few devices available to compare these modeling choices with reality, this first step should explore the issues of pure modeling and software tools.

During the project, depending on the availability of new QuBits devices, these first versions of compact models can be compared and enhanced to improve modeling methodology (in correlation with experimental data).

This work will build on the shared skills of LSM and LICL (and collaboration with INCAC), and their habit of working together.

The candidate should have deep understanding of Qbit (experimental and / or theoretical) and if possible a knowledge of SPICE, NEGF or TCAD in their CMOS point of view.

  • Keywords : Engineering science, Electronics and microelectronics - Optoelectronics, DCOS, Leti
  • Laboratory : DCOS / Leti
  • CEA code : PsD-DRT-18-0056
  • Contact : sebastien.martinie@cea.fr

Development of a cell analysis algorithm for phase microscopy imaging

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Start date : 1 September 2018

offer n° PsD-DRT-18-0089

At CEA-Leti we have validated a video-lens-free microscopy platform by performing thousands of hours of real-time imaging observing varied cell types and culture conditions (e.g.: primary cells, human stem cells, fibroblasts, endothelial cells, epithelial cells, 2D/3D cell culture, etc.). And we have developed different algorithms to study major cell functions, i.e. cell adhesion and spreading, cell division, cell division orientation, and cell death.

The research project is to extend the analysis of the datasets produced by lens-free video microscopy. The objective is to study a real-time cell tracking algorithm to follow every single cell and to plot different cell fate events as a function of time. To this aim, researches will be carried on segmentation and tracking algorithms that should outperform today’s state-of-the-art methodology in the field. In particular, the algorithms should yield good performances in terms of biological measures and practical usability. This will allow us to outperform today’s state-of-the-art methodology which are optimized for the intrinsic performances of the cell tracking and cell segmentation algorithms but fails at extracting important biological features (cell cycle duration, cell lineages, etc.). To this aim the recruited person should be able to develop a method that either take prior information into account using learning strategies (single vector machine, deep learning, etc.) or analyze cells in a global spatiotemporal video. We are looking people who have completed a PhD in image processing, with skills in the field of microscopy applied to biology.

  • Keywords : Engineering science, Life Sciences, Biotechnology, biophotonics, Cellular biology, physiology and cellular imaging, DTBS, Leti
  • Laboratory : DTBS / Leti
  • CEA code : PsD-DRT-18-0089
  • Contact : cedric.allier@cea.fr

Conformal deposition of polymer thin-films in high aspect ratio 3D structures

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Start date : 1 June 2018

offer n° PsD-DRT-18-0078

The deposition of thin films on challenging high aspect ratio structures are of key importance in many different areas of microelectronics and nano-technologies. For polymer thin films, filament-assisted CVD techniques (such as iCVD) have emerged recently as promising method for the conformal deposition of insulating thin films in 3D structures. However, it is still not clear if this CVD method can allow conformal coating inside porous and 3D substrates with acceptable growth rates and what are the limits of utilization. The work proposed here aims to study polymer thin film deposition by iCVD in high aspect ratio 3D structures in order to identify the parameters governing the deposition speed and the accessible degree of conformality. The works will be performed on high aspect ratio Through Silicon Vias and on various porous substrates. The candidate will be in charge of thin films deposition on a 200 mm tool and of the material characterization. The thin films will be characterized using physicochemical analyses (FTIR, X-Ray Reflectometry, Ellipsometry, Porosimetry, Contact angle, AFM). More in depth characterizations (using Electronic Microscopy, ToF-SIMS) will be carried out to study the deposition in 3D structures.

The main objective of the work will be to identify the key parameters that play a role in the conformal deposition inside 3D structures and porous substrates as a function of the feature shape and size. The work will be done in the LETI/DTSi division. The material deposition and characterizations will be performed in the LETI clean room in close collaboration with an industrial partner. Part of the work will be done in collaboration with experts of materials characterization (CEA nanocharacterization platform), and specialists in charge of 3D integration.

  • Keywords : Engineering science, Materials and applications, Solid state physics, surfaces and interfaces, DTSI, Leti
  • Laboratory : DTSI / Leti
  • CEA code : PsD-DRT-18-0078
  • Contact : vincent.jousseaume@cea.fr
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