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Offers : 24

Characterization and modeling of Si and III-V FET devices under deep cryogenic condition

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Start date : 6 January 2020

offer n° IMEPLaHC-09112019-CMNE

Institut de Microélectronique, Electromagnétisme et Photonique
IMEP-LaHC, Grenoble INP, BP 257
MINATEC
38016 Grenoble cedex 16, France

 

PhD Position

Topic: Characterization and modeling of Si and III-V FET devices under deep cryogenic condition
Start: January 2020
Salary: 1400 EUR / month (net)

Context :
Quantum computing is currently attracting a lot of research due to its high potential for complex calculation and cryptography applications. The core elements of quantum computing are Qbits, but they must be addressed and accessed using an embedded CMOS technology, which hence needs to operate at very low temperatures, as Qbit devices only operate in cryogenic conditions. The understanding of MOSFET operation at very low temperature is well known since the 90s, but modern and emerging technologies like FDSOI, FinFET, III-V HEMT or NanoWire, which will be needed in the framework of quantum computing, have not been extensively studied at low temperature. One particular property of these technologies is their high surface to volume ratio and their use of high-K materials, which may lead to an undesired increased impact of electronic noise, related to the presence of traps and defects, extremely detrimental for quantum computing. In addition, MOSFET devices generate heat, which impacts their own operation, in a phenomenon called the Self Heating Effect (SHE). This effect is still not fully understood yet, especially at low temperature. Therefore, the cryogenic behavior of these new MOSFET architectures has to be fully re-investigated in the light of their future use for quantum computing application.

In order to face these exciting challenges and in the framework of this proposed PhD subject, the student will perform a detailed experimental study of Si and III-V FET electrical properties and reliability in cryogenic conditions (down to 4K), using the state-of-the-art facilities of IMEP-LAHC. This work will then be followed by the development of physical models, which will be used by teams of circuit designers, in the framework of a European project (SEQUENCE) whose general objectives are:

  • To provide technology for scalable cryogenic electronics supporting emerging quantum computing technologies.
  •  To mature a selected set of emerging device technologies (TRL 4) with technology benchmark to support future technology nodes.
  • To establish the optimal balance between III-V, Si CMOS, and emerging device technologies to meet the power and form factor constrains in cryogenic electronics and develop 3D technology integration strategies.

Detailed overview of the PhD subject :

  1. Advanced cryogenic electrical characterization
    The PhD student will perform a detailed electrical characterization from room temperature down to 4K, on various Si and III-V MOS devices, fabricated by the partners of SEQUENCE (LETI/CEA, Lund University, IBM Zurich). The challenges include proper assessment of electrical properties of devices through Capacitance-Voltage and Current -Voltage measurements measurements on devices featuring short gate length and small width (nanometrics sizes).  Magneto-transport measurements down to 4K and up to 9 Teslas will also be carried out to evaluate more precisely the channel transport mechanisms by Hall effect and magnetoresistance phenomena.
  2.  Interface and dielectric trap characterization
    The PhD student will perform a refined analysis of the device gate dielectric-channel interface quality based on low frequency noise (LFN), random telegraph noise (RTN) and Charge Pumping (CP) measurements. The origin of different noise sources will be identified, aiming in the proper trap
    parameter extraction and noise modeling. In small area devices in particular, the onset of RTN will be investigated for comparison to the usual 1/f (flicker) noise and additionally provide single defect characteristics.
  3. Self heating effect characterization
    The PhD student will carry out SHE electrical characterization by specific pulsed I-V measurements  on various selected devices in order to benchmark different device architectures and technologies. The techniques of gate thermometry and thermal microscopy may also be examined.
  4. Modelling and simulation
    The PhD student will also conduct a physical modelling of the operation of such Si/III-V FET devices based on Poisson-Schrodinger simulation carried out at deep cryogenic temperatures. She/He will focus both on charge and capacitance characteristics, transport properties as well as on low frequency noise modelling, in order to better interpret the experimental data on one hand, and examine the device behavior in a circuit, through Verilog-A model development.

Environment
IMEP-LaHC (MINATEC)  benefits from a renowned expertise in low temperature characterization and modelling of CMOS devices since the end of 80s, with emphasis on MOSFET parameter extraction, LF noise and transport in inversion layer at cryogenic temperatures for space applications.
IMEP-LaHC has also founded the workshop on low temperature electronics (WOLTE) in 1994, still running today. In the framework of the European project SEQUENCE, IMEP-LaHC will contribute to the characterization and modeling of Si and III-V MOS devices fabricated at LETI/CEA (Grenoble), Lund University (Sweden) and IBM Zurich (Switzerland).

Requirement
The student should have knowledge of electronics and semiconductor physics, as well as basic understanding of semiconductor device operation principles and applications. Technical skills regarding data treatment through Origin, MATLAB, Mathcad or Python will be needed. Already acquired experience in electrical characterization will be appreciated.

Contact
PhD supervisor: Prof F. Balestra, , DR CNRS, francis.balestra@grenoble-inp.fr (+33456529510)
PhD co-supervisor: Dr. C. Theodorou, CR CNRS,  christoforos.theodorou@grenoble-inp.fr (+33456529549)

  • Keywords : Engineering science, Electronics and microelectronics - Optoelectronics, FMNT, IMEP-LaHc
  • Laboratory : FMNT / IMEP-LaHc
  • CEA code : IMEPLaHC-09112019-CMNE
  • Contact : francis.balestra@grenoble-inp.fr

Realization and optimization of SiC based nanowires Electrical Field Effect (NWFETs) biosensors for direct electrical detection of molecules

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Start date : 1 October 2019

offer n° IMEPLaHC-06062019-CMNE

                                                              

Realization and optimization of SiC based nanowires Electrical Field Effect (NWFETs)
biosensors for direct electrical detection of molecules

Topic :

The development of label-free biosensors based of electrical detection of molecules is of great interest for early diagnosis of biomarkers in personalized medicine, environmental monitoring and bio-defense. In this aim, many studies are currently being carried out on sensing devices based on semiconductive silicon nanowires, for electrical detection of DNA or proteins by field effect with high sensitivity and specificity [1].
However, silicon nanowires exhibit some physicochemical instability when immerging in saline physiological solutions. It leads to some non-reliability of the measurements which, in fact, become limiting. To overcome these critical issues, other kinds of semiconducting nanomaterials or new nanowire architectures involving Si core with a passivating metal oxide shell are under investigation. In particular, silicon carbide (SiC) is a semiconductor which can advantageously replace silicon.
Indeed, SiC is already used for many biomedical applications: covering of prostheses and stents, biomimetic structures and cell reconstruction. Very recently, it has emerged as the best semiconductor candidate, chemically inert, biocompatible [2], which offers new perspectives notably for integration of in-vivo sensors. Notably, our group has recently proved the superior chemical stability of SiC NWs over Si NWs [3] in physiological conditions.
Since several years, our group is a leading group implementing SiC based Nanowires Field Effect Transistors (NWFETs) for different applications: nanoelectronics in critical environments (temperature, gas, radiation) and nanosensors of biological molecules (DNA). We have validated the concept of SiC nanowire transistors in previous PhD theses leading to a first demonstrator on an international scale.

The grafting and electrical detection of DNA using NWFETs based on 2 types of innovative SiC nanostructures have been demonstrated [4-8]. As a continuation of this work, this new PhD thesis aims to develop biosensors involving SiC based nanolines optimizing thoroughly the characteristics and performances of these devices in terms of sensitivity, detection limit, selectivity long-term functionality and real-time acquisition.

Objective:
The thesis work will focus on the development of SiC based nanolines, their integration in NWFETs, their electrical characterization, their functionalization and integration in microfluidic cells in order to be able to emphasize the electrical detection of DNA or proteins in liquid medium. The work will be principally done within 2 Grenoble laboratory partners in this project: IMEP-LaHC and LMGP.
This partnership is supplemented by surrounding technical platforms (CIME Biotech, clean rooms PTA and CIME).

Candidate profile:
The candidate should be Master of Sciences graduated in the field of Micro-Nanotechnology.
An experience in biosensing and cleanroom processing and device characterization would be a plus.
CV, marks of master (year 1 and 2) and letter should be sent before July , 15 to supervisor and co -supervisor .

Contact:
Edwige BANO,   IMEP-LaHC  : Supervisor
Valérie STAMBOULI, LMGP : Co -supervisor

Funding:
fellowships from EEATS doctoral school

Starting date:
1st October 2019

References:
[1] N. Gao, et al, 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] R. Bange, et al, Material Research Express 6, 015013 (2019)
[4] L. Fradetal, thesis of Grenoble University (2014)
[5] L. Fradetal, et al, Journal of Nanoscience and Nanotechnology 14, 5, p3391–3397 (2014)
[6] J.H.Choi et al, Journal of Physics D: Appl. Phys. 45 p235204 (2012)
[7] M. Ollivier et al, J. Crystal Growth 363 p158-163 (2013)
[8] L. Fradetal et al, Nanotechnology 27 (23) p235501 (2016)

 

  • Keywords : Engineering science, Electronics and microelectronics - Optoelectronics, FMNT, IMEP-LaHc
  • Laboratory : FMNT / IMEP-LaHc
  • CEA code : IMEPLaHC-06062019-CMNE
  • Contact : edwige.bano@grenoble-inp.fr

Second harmonic generation for semiconductor materials and interfaces characterization

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Start date : 1 October 2019

offer n° IMEPLaHC-06052019-CMNE

Second harmonic generation for semiconductor materials and interfaces characterization

IMEP – LAHC, MINATEC – INPG, 3, Parvis Louis Néel, 38016, Grenoble

Advisors/contacts:

Irina Ionica , 04 56 52 95 23
Guy Vitrant
Lionel Bastard

Context:
This PhD topic is financed within the French national plan Nano 2022, which is a part of the European project IPCEI “Nanoelectronics for Europe” and has the aims to support micro/nanoelectronics industry. Among its 5 strategic axes, smart sensors (such as the image sensors) occupy an important place.
The improvement in performances of such devices requires continuous technological optimizations of the materials and interfaces constituting them. Most of the times, the materials used are thin film layers (or stacks containing multiple thin films) and their non-destructive, full-wafer characterization is really challenging.

PhD objectives and work-to-do:
The objective of this PhD is to develop an innovative characterization method for multi-layers of high-k dielectrics used for silicon passivation. The method uses the second-harmonic generation (SHG), which is a non-linear optics phenomenon. The particularity of the SHG generated by centrosymmetric materials (such as Si, Al2O3, HfO2…) is that the signal, mainly coming from interfaces’ contributions, is very sensitive to the electrical field present there. For image sensors, both high interface quality and field-effect passivation are required and both of them can actually be measured by the SHG1. These objectives require two key elements to be handled in the PhD: (1) deconvolution of optical propagation phenomena in order to access electrical properties of the interface and (2) calibration of the SHG using other electrical measurements such as capacitance versus voltage on structures specifically fabricated in clean-room.
The topic is therefore multidisciplinary (semiconductor physics, semiconductor device physics, non-linear optics …) and convers the full spectrum from simple test-structures fabrication, to SHG measurements and modeling and to electrical characterization and parameters extraction.

Scientific environment and collaborations:
The PhD student will benefit from innovative equipment: a unique prototype in Europe, installed at IMEP-LAHC in 2014.
Additionally, we developed a home-made optical simulator in order to explain the experimental results. The student will also benefit from samples of high interest to the imaging sensors, from STMicroelectronics. The topic is thus strongly connected to both academic and industrial world, since it covers the physical understanding and the pragmatic applications for microelectronics.

Knowledge and skills required:
This Ph.D. topic belongs to the micro-nano-electronics field but it is multidisciplinary (non-linear-optics, electrical characterization and modeling of semiconductor-dielectric interfaces). The candidate must have a solid knowledge in at least one of these fields. Her/his scientific curiosity and open-mindedness should allow her/him to acquire the other technical skills. The candidate is expected to enjoy both experimental and simulation work. Scientific curiosity and rigor, motivation, seriousness and creativity are mandatory qualities in order to take full advantage of the scientific environment of this thesis and to gain excellent expertise for her/his future career. The topic is close to both fundamental physics and industrial world; after the Ph.D. the candidate should be able to easily adapt to both academic and industrial research environments.

The candidate must have a very good academic record, with high grades.
1 M.L. Alles et al, IEEE Transactions on Semiconductor Manufacturing, vol. 20, 107 (2007)
D. Damianos et al, Solid State Electronics, vol. 115, p.237, 2016

  • Keywords : Engineering science, Electronics and microelectronics - Optoelectronics, FMNT, IMEP-LaHc
  • Laboratory : FMNT / IMEP-LaHc
  • CEA code : IMEPLaHC-06052019-CMNE
  • Contact : Irina.Ionica@phelma.grenoble-inp.fr

Investigating the polarity related properties of well-ordered ZnO nanowires for piezoelectric devices: The issue of defects & hydrogen

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Start date : 1 October 2019

offer n° LMGP2019-2

Topic:

The development of semiconductor nanowires (NWs) is of great basic and technological interests owing to their high aspect ratio at nanoscale dimensions, giving rise to novel, remarkable properties, as well as a broad range of potential applications. Among them, ZnO as an abundant and biocompatible compound semiconductor with attractive properties has been receiving increasing interest over the last decade. It crystallizes into the strongly anisotropic wurtzite structure, which is both polar and piezoelectric. Its ability to grow as NWs oriented along the polar and piezoelectric ±[0001] (i.e., c) axis by a number of deposition techniques including the low-cost and low-temperature chemical bath deposition is of great importance for its use in nanoscale engineering devices. The efficient integration of ZnO NWs into the engineering piezoelectric devices to name a few requires the precise control of the uniformity of their structural morphology over large surface areas. This is typically achieved by selective area growth using pre-patterned nucleation surfaces by technological processes in a cleanroom environment (i.e. advanced lithography and etching). Two correlated fundamental properties that have crucial effects on the piezoelectric device performances are the polarity and the nature and the defect density. We have shown, for the first time, in 2014 the formation of O- and Znpolar ZnO NWs, opening the way for more deeply analyzing their effects, which are critical as reported in ZnO single crystals and films. Interestingly, the nature and the density of the defects are related to surface terminations at the NW top facet and thus to polarity. However, these characteristics are not known in ZnO NWs, although they drastically govern the performances of the engineering devices. In particular, hydrogen has recently emerged as a major source of defects in ZnO NWs, but very little is currently known about this subject. The thesis project aims at elucidating the present polarity as well as the nature and density of defects (especially defects in connection with hydrogen) on well-ordered O- and Zn-polar ZnO NWs formed by combining selective area growth with chemical bath deposition in LMGP by correlating advanced characterization experiments as transmission electron microscopy, Raman spectroscopy, Fourier Transformed infrared spectroscopy, tunnel microscopy equipped with local probes, X-ray photoelectron spectroscopy with ab initio calculations to simulate the position of H inside the ZnO structure. Following this fundamental investigation, the fabrication of piezoelectric devices will be considered to directly show the beneficial effects on the device performances.

Scientific environment:

The applicant will work in the LMGP, Materials and Physical Engineering Laboratory inside the Nanomaterials and Advanced heterostructures team in close collaboration with the Aristotle university of Thessaloniki, Physics department in Greece for the ab initio calculations and neighbour laboratories in Grenoble (i.e. Institut Néel, …) for specific characterisation techniques. Located in the heart of an exceptional scientific environment, the LMGP offers the applicant a rewarding place to work. LMGP Web Site: http://www.lmgp.grenoble-inp.fr/ PhD thesis duration: 36 months from Fall 2019

Required background:

The applicant should have an Engineering degree and/or a Master of Science in materials physics and chemistry, nanosciences, and/or semiconductor physics. Specific skills regarding team work and English abilities will be required for her/his integration into the team and for taking part in the ongoing international collaborations. Fundings: IMEP-2 Doctoral School (priority PhD thesis topic)

Closing date for applications: 1st of June 2019

  • Keywords : Engineering science, Electronics and microelectronics - Optoelectronics, Materials and applications, LMGP
  • Laboratory : LMGP
  • CEA code : LMGP2019-2
  • Contact : eirini.sarigiannidou@grenoble-inp.fr

Transparent electrodes based on silver nanowires-nanocellulose: from fundamental aspects to device integration

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Start date : 8 April 2019

offer n° 2019-1

A phD position is offered between LMGP and LGP2 laboratories. The appointment has a fixed duration of 36 months, starting 01/10/2019.

You will be hired in the framework of a Regional project (2018-2023) called “Eternité” and dealing with research and development devoted to optically transparent materials and electrical conductors that has attracted growing interest in recent years for many applications. These are a key technological element for a large number of devices such as solar cells, efficient lighting (LEDs, OLEDs), touch screens, smart windows, transparent heating films, etc. The objectives of the ETERNITY project are to design and develop transparent electrodes that are: i / efficient (i.e. the most transparent and conductive possible); ii / stable through the production of nanocomposites via an innovative thin film deposition technique (either a thin oxide layer or the use of nanocellulose); iii / flexible (thanks to the use of metal nanowires (MNW) and nanocellulose which are ductile) on flexible substrates (especially polymers), iv / low cost and finally v / integrable within devices whose economic potential is strong and in full development and for which many industrial partners are present at both regional and national levels. The partners LMGP and LGP2 have independently developed in recent years specific expertise on stable and efficient electrodes based on silver nanowires (LMGP [1,2]) and AgNW/nanocellulose hybrids composites (LGP2 [3,4]). The combination of these two complementary laboratories will allow a good synergy to obtain efficient and durable transparent electrodes and thin films whose integration will easily be the object of collaborations with the industrial sector. The actions carried out in this PhD project concern the development of materials for the fabrication of these nanocomposites, their characterization and their physical modelling. Their integration into real devices will also be performed. This Thesis offers a good trade-off between fundamental and experimental aspects. The candidate will get precious knowledge and skills in physics, nanomaterial sciences and nanocellulose. The LMGP/LGP2 house state of the art experimental equipment to fabricate AgNW networks and nanocellulose with adapted tools for their physical characterizations.

Related references:
[1] T. Sannicolo, M. Lagrange, A. Cabos, C. Celle, J.-P. Simonato, D. Bellet, Small, 12 (2016) 6052;
[2] T. Sannicolo, N. Charvin, L. Flandin, S. Kraus, D. T. Papanastasiou, C. Celle, J. Simonato, D. M. Rojas, C. Jiménez, D. Bellet, ACS Nano (2018), 12, 4648;
[3] F. Hoeng, A. Denneulin, G. Krosnicki, J. Bras, J . of Mat. Chem. C 46 (2016) 10945;
[4] F. Hoeng, A. Denneulin, N. Reverdy-Bruas, G. Krosnicki, J. Bras, Applied Surf. Science 394 (2017) 160.

Research profile & skills (required / highly desirable): We are looking for a highly motivated student with a master degree in materials science or physics/chemistry, and who is interested to work in an inter-disciplinary project. Interpersonal skills, dynamism, rigor and teamwork abilities will be appreciated. Candidates should be fluent in both oral and written English.

Scientific environment:
The candidate will work within the LMGP (Materials and Physical Engineering Laboratory) in the FunSurf group and the LGP2 (Laboratory of Pulp and Paper Science and Graphic Arts) in the MatBio and FunPrint groups. Located in the heart of an exceptional scientific environment, both LMGP and LGP2 offer the applicant a rewarding place to work.

LMGP Web Site: http://www.lmgp.grenoble-inp.fr/ LGP2 Web Site: http://pagora.grenoble-inp.fr/en/research

Salary: Pay scale of a fixed term post as a G-INP Researcher: 2315 €/month (gross salary, net salary: – 20%)

Application procedure: Please send motivation letter, CV, list of scientific publications and the contact information of a reference person (with e-mail & phone number) to:

Daniel Bellet: daniel.bellet@grenoble-inp.fr (04 56 52 93 37);
Julien Bras : julien.bras@grenoble-inp.fr (04 76 82 69 15) ;
Aurore Denneulin: aurore.denneulin@grenoble-inp.fr (04 76 82 69 28) ;
David Muñoz-Rojas : david.munoz-rojas@grenoble-inp.fr (04 56 52 93 36).

Closing date for applications: 22th of April 2019

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