Offers : 107
QCL lasers on Si coupled with an optical waveguide
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
- Contact : firstname.lastname@example.org
Numerical and analytical studies on the synchronisation of spintorque oscillators
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 : email@example.com
Realization and optimization of biosensors based on SiC nanolines for DNA electrical detection
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  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 , 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.
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:
- 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) .
– 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).
- 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).
- 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 , and on the other hand, the electron beam lithography (LMGP) . Electrical characterization of biosensors will be conducted on both technological variants and between each functionalization steps (IMEP).
- 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).
 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)
 S.E.Saddow, Silicon Carbide Biotechnology: A Biocompatible Semiconductor for Advanced Biomedical Devices and Applications. Elsevier Sciences (2011)
 K. Rogdakis, thèse de l’Université de Grenoble (2010)
 J.H. Choi, thèse de l’Université de Grenoble (2013)
 M. Ollivier, thèse de l’Université de Grenoble (2013)
 L. Fradetal, thèse de l’Université de Grenoble (2014)
 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)
 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)
 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)
 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 , firstname.lastname@example.org
Valérie STAMBOULI , LMGP , email@example.com
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 : firstname.lastname@example.org
Hybrid nanowires for topological quantum computing
Start date : 1 September 2018
offer n° SL-DRF-18-1006
One interesting and promising proposal for quantum computation relies on the so-called topological protected quantum bits. Realizing such quantum bits depends on the ability to make materials that can host Majorana bound states. In 2012, signatures of such states were reported in one-dimensional semiconductors with high spin-orbit coupling, coupled to a superconductor . Since then, nanostructured hybrid materials based on superconductor/semiconductor interfaces have received increased attention. Yet, controlled formation of topological protected states can only be realized if the superconductor/semiconductor interface is of high quality. Creating those interfaces in an epitaxial fashion would have many advantages, among them better transparency, controlled interface chemistry, higher current injection and lower disorder. However, combining crystalline metals and semiconductors is challenging because of the fundamental different properties of both families of materials. Recently, in-situ epitaxial growth of InAs/Al core/shell nanowires exhibited defect free and homogeneous interfaces . The devices revealed a superconducting hard gap demonstrating the high potential of in-situ shell epitaxy. Here, we propose to develop novel interfaces using a higher critical field superconductor such as vanadium to reach the Majorana regime and to perform further topological experiments.
 V. Mourik et al 2012 Science 336(6084) 1003
 P. Krogstrup et al 2015 Nature Materials 14 400
Research topic and facilities available:
In this project, the student will carry out the growth of networks of hybrid nanowires in a III-V molecular beam epitaxy reactor in CEA/INAC. In particular, she/he will focus on InAs/V core/shell nanowire fabricated using templates developed in the cleanroom. The student will perform the characterization of the samples by SEM, EDX and/or TEM. Together with partner labs in the USA, she/he will participate in several low temperature measurement campaigns throughout the course of her/his PhD, as well as perform high-end structural studies using advanced equipment and facilities.
- Keywords : Mesoscopic physics, Solid state physics, surfaces and interfaces, INAC, PHELIQS
- Laboratory : INAC / PHELIQS
- CEA code : SL-DRF-18-1006
- Contact : email@example.com
Synchronisation of wireless IoT networks under integration & consumption constraints
Start date : 1 October 2018
offer n° SL-DRT-18-0460
Application and research context :
One of main trends in Internet of Things (IoT) goes to low power consumption systems, entirely autonomous in their mission, with capabilities of operation in network ensuring the information transfer to ground or air based station.
For one of our future IoT applications in the context of local monitoring (Local Seismology, Microclimat, Local Airflow, Soil and crop state) using a network of spatially distributed sensors (hundreds in < 100m range between communication nodes) and a drone based station, the question of the information transfer from each node to the base station necessarily arises. The main problem happens during a short time fly-by over the nodes by the drone. Since the nodes are not necessarily all connected to the base station, the network information cannot be fully transferred to the base. In general, the communication phase being extremely power consuming, an asynchronous transfer approach cannot be used due to among others a high number of nodes in the network. Targeting the low power consumption for the overall network, low bandwidth for the communication channels (about 200Hz) and guarantee of the minimum communication time might be possible through the decentralized synchronization between the nodes where the base station is used as the reference. In this context, one has to ensure the synchronization of spatially distributed clocks (time domain criterion) together with spectral constraints for the carrier signal (frequency domain criteria).
The main objective is to find the most efficient clock synchronization solution based on the extensive use of signal processing and automatic control techniques that may deal with numerous aspects of the initial application specification such as synchronization constraints expressed in time and frequency domains as well as the decentralized character of the problem.
Scientific challenges and possible contributions :
This thesis will tackle new scientific challenges coming actually to the IoT from the ultra-low consumption needs, distributed architectures, and Ultra Narrow Band communication specifications. The first challenge consists in introducing a clock synchronization algorithm that involves uncertain/dynamic delays between nodes and the base station signals that are unavoidable and often neglected by the State-of-the-Art. The second challenge is to face the variable character of the interconnection topology between nodes and the base station due to the fly-by phase. In that case the base station will not constantly have connection to a chosen node but fly through a sequence of one or multiple nodes with varying IDs during the fly-by. The relative Doppler frequency shift will have impact on the network operation frequency.
Thus, the potential main contribution of the thesis is to propose a solution for a Control Theory Problem being not formulated before in the context of the communication network design. On the other hand, this solution allow to pave the way to the “quartzless” communication System on Chip (SoC) for IoT being extremely challenging since the constraints of overall consumption, frequency and phase stability are the main questions actually arise.
- Keywords : Engineering science, Automatics, Remote handling, Electronics and microelectronics - Optoelectronics, DACLE, Leti
- Laboratory : DACLE / Leti
- CEA code : SL-DRT-18-0460
- Contact : firstname.lastname@example.org