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Offers : 65

GaN/Si transistor compact modeling for power and RF-5G applications

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Start date : 1 October 2018

offer n° SL-DRT-18-0888

GaN RF devices are developped since more than 15 years by industrial companies and many research laboratories continue to improve this technology.

Leti wants to start a GaN/Si activity, mainly for 5G application. It will be based on Leti experience concerning GaN/Si device for power application. A first version of compact model was developped for Normally-ON transistor and is already available at Leti (Leti-HSP). Nevertheless, this model core (DC) needs to be consolidated and improved to justify its use for Normally-OFF transistor and then to be adapted to GaN-RF transistors, which are, at device structure level, very different from power devices.

Those model developpments are mandatory to determine the GaN/Si technology potential for power and RF applications.

Leti-HSP model was developped at Leti and well described device behavior (DC/AC) of GaN/Si power devices.

The first step of this PhD thesis will be to understand the existing model code (verilogA language) and to determine its force and weakness. A special focus will be needed on on the description of current stauration but also of moderate inversion regime both known as weaknesses of Leti-HSP model in terms of accuracy. Weaknesses analysis of the existing model will then be followed by the development of a new version with associated model, which will be provided to designers through a PDK (Process Design Kit)

Finally, after the study of differences between GaN/Si transistor for power and RF applications, the final objective of this PhD thesis will to to bring the mandatory modification to Leti-HSP model to guarantee its ability to describe GaN/Si device behavior in RF field.

Each activity listed above will be supported by:

• Power device compound integration laboratory of Leti with its strong expertise in GaN/Si device physics.

• Electrical characterization with the collaboration with the electrical characterization laboratory of Leti which already perform GaN/Si device characterization.

• TCAD simulation, performed by the PhD student in the simulation and modeling laboratory of Leti to deeply understand GaN/Si device behavior, to be able to build an analytical model.

  • Keywords : Engineering science, Electronics and microelectronics - Optoelectronics, DCOS, Leti
  • Laboratory : DCOS / Leti
  • CEA code : SL-DRT-18-0888
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Extreme elastic deformation of semiconductor materials for optoelectronic applications

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Start date : 1 October 2018

offer n° SL-DRT-18-0998

Extreme elastic deformation of materials has been proven to modify their physical properties paving the way to numerous innovative applications. The goal of this thesis consists in the homogeneous deformation of a crystalline film over a macroscopic surface up to levels never obtained so far by other methods. For semiconductors materials, such a deformation allows for an important modification of optical and electronic properties: For instance, the charge carrier mobility can be significantly enhanced in silicon under tensile strain while the band structure of germanium undergoes various modifications when exposed to strain. High tensile strain levels have led to change this indirect semiconductor into a new material in the sense of a quantitative (band gap) and qualitative (indirect-direct transformation) modification of electronic properties.

The intention of this thesis topics is to obtain the quantitative control of elastic strain imposed in a germanium crystalline film and to produce a proof of concept material for innovative industrial applications

  • Keywords : Engineering science, Electronics and microelectronics - Optoelectronics, Solid state physics, surfaces and interfaces, FMNT, LTM
  • Laboratory : FMNT / LTM
  • CEA code : SL-DRT-18-0998
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QCL lasers on Si coupled with an optical waveguide

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Start date : 1 March 2018

offer n° SL-DRT-18-0597

In the field of the mid infrared (wavelength from 3 to 12 µm), III-V Quantum Cascade Lasers on InP substrate are now in production with top performance levels. The coupling with an integrated optics circuit is at present realized by abutting a chip laser QCL on InP with a guided optics circuit of on silicon. This process is long and led to low tolerances of manufacturing and to high cost. The most promising solution is to put the QCL laser on the Si wafer and to couple it with the optical waveguides. For large manufacturing, the objective is to make collectively lasers QCL directly on the wafer with the means of the microelectronics. It is all the stake in this thesis where it will be necessary to design and to simulate the coupling of the QCL to an optical guide, to build the process steps with the help of the process engineers, to follow the manufacturing steps realized on our platform of manufacturing and finally to characterize these new components laser QCL coupled with an optical guide on our probe tester. A knowledge of photonics is desirable.

  • Keywords : Engineering science, Optics - Laser optics - Applied optics, DOPT, Leti
  • Laboratory : DOPT / Leti
  • CEA code : SL-DRT-18-0597
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Numerical and analytical studies on the synchronisation of spintorque oscillators

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Start date : 1 October 2018

offer n° SL-DRF-18-1012

Spintorque oscillators are based on magnetic tunnel junctions that provide a large oscillating output voltage signal in the GHz range when driving it with a DC current. The spin momentum counter-acts natural damping and can drive the magnetization into large angle steady state oscillations, which are converted into an electrical signal via the magneto-resistance. While in the past many studies have been realized on single spintorque oscillator devices, currently efforts concentrate on the coupling of different oscillators to enhance output signal levels and potentially reduce noise. Coupling and synchronisation of these oscillators can occur via electrical or dipolar interactions. This thesis will undertake a simulation study of the mutual synchronisation of such uniformly magnetized structures and will develop where possible an analytical frame work based on the descriptions we have developed within the group for injection locking to an external signal source. The different coupling mechanism are dipolar fields or the mutual rf current. The questions to address concern how the different coupling mechanisms influence the locking process, in particular the coupling phase. This will be of importance when more than two oscillators will be coupled that are not identical and that will compete with each other. Identifying the parameters that lead to stable coupling or chaotic states are of special interest.

  • Keywords : Solid state physics, surfaces and interfaces, INAC, SPINTEC
  • Laboratory : INAC / SPINTEC
  • CEA code : SL-DRF-18-1012
  • Contact :

Realization and optimization of biosensors based on SiC nanolines for DNA electrical detection

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Start date : 1 October 2018

offer n° IMEPLaHC-06112018-CMNE

PhD proposal 2018
Realization and optimization of biosensors based on SiC nanolines for DNA electrical detection

Scientific context :
The fast and direct detection of small quantities of biomolecules improves early medical diagnosis of certain serious diseases as cancers and can be used to detect in situ the presence of pathogenic viruses or GMOs for food industry, environmental protection and bio-defense. Currently, many research projects are conducted on nanoelectronic devices based on Si nanowires [1] that can perform such detection with very high sensitivity.
Indeed, SiC is already used for many biomedical applications covering prostheses and stents, biomimetic structures and cellular reconstruction. Very recently, it has emerged as the best candidate biocompatible semiconductor [2], which provides new integration prospects of in vivo sensors.

Objective of the research program :
Our research project aims to develop NWFETs (Nanowire Field Effect Transistors) based on SiC nanostructures for various applications: nanoelectronics in critical environments (temperature, gases, radiation) or nanosensor for temperature, gas or biological elements. This project fits in perfectly with one of the research department “Physics, Engineering and Materials” from University Grenoble Alpes (UGA), and in significant ongoing thematic programs at local, national and international level as Labex MINOS (Laboratory of Minatec Center on the Miniaturization of Innovative Nanoelectronics Devices), the IRT Nanoelectronics and Sinano Institute.
We have validated the concept of SiC nanowire transistors in previous phD thesis leading to a first demonstrator internationally [3, 4, 5]. Grafting and electrical detection of DNA through NWFET based on 2 types of innovative SiC nanostructures have been demonstrated [6, 7, 8, 9, 10]. In continuation of this work, this new phD thesis aims to develop biosensors based on eached nanolines and to optimize the properties and performances of this device in terms of sensitivity, detection limit, reversibility, stability, selectivity and acquisition time.

Workplan :
In this PhD project, the student will support the development of SiC nanolines, the realization of NWFET transistors, their functionalization towards the electrical detection of DNA. The work will be done within 2 Grenoble laboratory partners in this project: IMEP (Grenoble site of IMEP-LAHC) and LMGP.
The 4 main steps of the program are:

  1. Development of SiC nanolines by two methods:
    – By ICP (Inductively Coupled Plasma) etching of nanolines into a SiC epitaxial layer of high quality and controlled doping (IMEP) [4].
    – By ICP etching of nanolines into a Si film on SOI (Silicon On Insulator) following by a carburation of these Si nanolines in a dedicated reactor to the epitaxial growth CVD (Chemical Vapor Deposition) to obtain Si core / SiC shell nanolines (collaboration avec Univ. Parme et Univ South Florida).
    Techniques such as atomic force microscopy AFM, transmission microscopy TEM, Raman spectroscopy and photoelectron spectroscopy XPS will be used for physical characterization and optimization of the resulting nanostructures (LMGP).
  2.  Technological achievement of NWFET:
    Backgated nanodevices, based on these SiC nanostructures, will be carried out with the upstream facilities of the Advanced Technology Platform (PTA) in Minatec using deposition and etching techniques, and also advanced ebeam lithography and lift-off techniques for achieving optimized microcontacts (IMEP).
  3.  Functionalization and hybridization:
    The covalent grafting of DNA probes on the two types of nanostructures will be realized in a localized manner by combining, on the one hand, an appropriated chemical functionalization process [7], and on the other hand, the electron beam lithography (LMGP) [8]. Electrical characterization of biosensors will be conducted on both technological variants and between each functionalization steps (IMEP).
  4.  Electrical detection of DNA: evaluation and performance optimization
    After the electrical detection of hybridization molecules, experiments will focus on assessing and optimizing performance: study of the sensitivity, detection limit, selectivity, stability and reversibility.
    Techniques such as current measurement (static and temporal), impedance, electrical noise, will be used on both variants of NWFETs (IMEP). Furthermore, the real-time acquisition will be studied and developed by the establishment of microfluidic systems (LMGP).


[1] N. Gao, W. Zhou, X. Jiang, G. Hong, T-M Fu, C.M. Lieber, “General Strategy for Biodetection in High Ionic Strength Solutions Using Transistor-Based Nanoelectronic Sensors”, Nano Letters. 15, p2143−2148 (2015)
[2] S.E.Saddow, Silicon Carbide Biotechnology: A Biocompatible Semiconductor for Advanced Biomedical Devices and Applications. Elsevier Sciences (2011)
[3] K. Rogdakis, thèse de l’Université de Grenoble (2010)
[4] J.H. Choi, thèse de l’Université de Grenoble (2013)
[5] M. Ollivier, thèse de l’Université de Grenoble (2013)
[6] L. Fradetal, thèse de l’Université de Grenoble (2014)
[7] L. Fradetal, V. Stambouli,, E. Bano, B. Pelissier, J.H. Choi, M. Ollivier, L. Latu-Romain, T. Boudou, I. Pignot-Paintrand, “Bio-Functionalization of Silicon Carbide Nanostructures for SiC Nanowire-Based Sensors Realization”; Journal of Nanoscience and Nanotechnology 14, 5, p3391–3397 (2014)
[8] J.H.Choi, L.Latu-Romain, E.Bano, F.Dhalluin, T.Chevolleau, T.Baron, ”Fabrication of SiC nanopillars by inductively coupled SF6/O2 plasma etching”, Journal of Physics D: Appl. Phys. 45 p235204 (2012)
[9] M. Ollivier, L. Latu-Romain, M. Martin, S. David, A. Mantoux, E. Bano, V. Soulière , G. Ferro, T. Baron, “Si–SiC core–shell nanowires”, J. Crystal Growth 363 p158-163 (2013)
[10] L. Fradetal, E. Bano, G. Attolini, F. Rossi, and V. Stambouli, “A Silicon Carbide nanowire field effect transistor for DNA detection”, Nanotechnology 27 (23) p235501 (2016)

Financial support :
The doctoral contract will be financed by University Grenoble Alpes in the framework of the Doctoral School EEATS.

The candidate is Master of Sciences graduated in the field of Micro-Nanotechnology. An experience in cleanroom processing and device characterization would be a plus.
CV, marks of master (year1 and 2) and letter should be sent to supervisor and co –supervisor by June 10, 2018 for an application on June 12, 2018 :
Edwige BANO , IMEP- LAHC ,
If its application is approved, the candidate will have to registered in the Doctoral School EEATS :



  • Keywords : Engineering science, Engineering science, Electronics and microelectronics - Optoelectronics, FMNT, IMEP-LaHc, LMGP
  • Laboratory : FMNT / IMEP-LaHc / LMGP
  • CEA code : IMEPLaHC-06112018-CMNE
  • Contact :
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