Offre de stages, thèses et postDocs MINATEC

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165 results found

[Thesis]

RF & millimeter-wave interposers for 3D integration. Transmission lines & vias based on nanowire’s membranes.

Offer N°: 8384

Start date: 1 Sep 2012

Required diploma : Master
Duration : 3 years
Required competences: Microwaves, electromagnetism, electronics, microelectronics

Keywords
RF & Millimeter waves. Interposer. High rate communications (6 Gbits/s – 60 GHz). Anti-collision radars (77-81 GHz). Imaging (94 GHz, 140 GHz). Nanotechnologies.

Description

Context and aims
Nowadays, there is a strong need for advanced communication systems in the millimeter-wave (mmW) frequencies for applications like high-data rate telecommunications as fast video-streaming (from 57 GHz to 66 GHz in Europe), automotive radars (76 GHz to 81 GHz), RF-imaging (94 GHz, 140 GHz and above). In this context, systems integration is of major interest. However present systems are still limited by passive devices. Baluns, power dividers, matching networks suffer from big dimensions and substrate losses. As a solution, 3D-integration of the devices by means of an interposer seems to be very accurate. An interposer is a performing high-frequency substrate[3], enabling active chips interconnections, on the front side, or from front to back side (thanks to low resistive and low inductive vias). As in Figure 1, low loss passives may be enfaced.

This PhD deals with a totally new, specific interposer, which principle has just been patented by the team proposing the subject[4], It consists in an alumina membrane filled with metallic nanowires, covered by a thin top layer of oxide, as shown in Figure 1. This leads to a focus of the electric field in the oxide layer to finally obtain a strong slow wave effect. Hence very high quality factor transmission lines can be realized. The presence of nanowires opens the way towards very performing vias, conventional, coaxial or coplanar, in direct competition with the usual Through Silicon Vias (TSVs) with resistance of 0.06  instead of 0.2 .

Figure 1. Transceiver module with miniaturized passive devices and different types of vias on the same metallic nanowires based membrane substrate
Practical work
In a first time, the PhD will have to become familiar with slow-wave transmission lines and vias on the nanowires based membrane, and their 3D electromagnetic simulation. Simulating tools are available at the IMEP-LAHC laboratory, and the simulation environment has already been optimized. The PhD will be part of a team very familiar with the mmW aspects. However, metallic nanowires membranes are a completely new topic (see the patent deposit date). The realization of the membranes, the transmission lines and the vias, in a first time, then the realization of more complex passive devices in a second time, will have to be put in place and optimized by the candidate him or herself. Finally circuit characterization will take place at the IMEP-LAHC. The IMEP-LAHC has facilities for high frequency vector network measurements: 300 mm tip prober connected to a 2 ports 110 GHz Vector Network Analyzer (VNA), tip prober connected to a differential VNA (up to 67 Hz, which enables the W-HDMI components characterization).

Contact:
Thesis supervisor:Philippe Ferrari, Professor, Head of the RF & Millimeter group, IMEP-LAHC.
Philippe Ferrari, Tel. : 00 33 4 56 52 95 68, philippe.ferrari@ujf-grenoble.fr

Co-supervisor: Florence Podevin, Assistant professor, RF & Millimeter group, IMEP-LAHC

Funding: from the French Ministry for High Education and Research

[3], Usually, high-resistive silicon or glass.
[4], P. Ferrari, G. Rehder, A. Serrano, F. Podevin, A.-L. Franc, « High frequency slow wave transmission lines », Patent deposit N° 12/53759, 24th of April 2012.

Keys words: RF Devices & Systems
Laboratory:FMNT / IMEP-LAHC
CEA code:
Contact: ferrari@minatec.inpg.fr

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[Thesis]

Design & realization of millimeter-wave phase shifters for beam-forming systems. Application to point-to-point high-data rate communications and automotive radars.

Offer N°: 8382

Start date: 1 Sep 2012

Required diploma : Master
Duration : 3 years
Required competences: Microwaves, electromagnetism, electronics, microelectronics

Key words
Millimeter-wave frequencies. NEMS/MEMS technology. High-data rate communications (6 Gbits/s – 60 GHz), automotive radars (77-81 GHz), RF & mmW imaging (94 GHz, 140 GHz).

Context & objectives
IMEP-LAHC holds a patent concerning a new concept for the development of MEMS-based millimeter-wave phase shifters[3]. This concept leads to very powerful devices, with very low insertion loss, and hence high RF performances[4].
The objective of the thesis work will be to develop a complete front-end module for beam-forming applications at millimeter-wave. The applications of such a system, not available yet, are very important: high-data-rate video-streaming, HDMI TV links, short range point-to-point communications, wireless sensors for medical applications, automotive radars, … All these applications are concerned by frequencies comprised between 55 GHz and 110 GHz.
Figure 1 and Figure 2 give the principle of the millimeter-wave phase shifters.
Several technologies can be used for the realizations, the choice being made during the beginning of the thesis:
·       Technology developed at CEA-LETI[5] for RF MEMS switches.
·       CMOS post-process technology.
·       Technology developed in IMEP-LAHC and PTA-MINATEC clean-rooms.

Figure 1 . Principle of the slow-wave propagation transmission lines (slow-wave coplanar waveguides or S-CPW).

Figure 2 Principle of the tunable phase shifters described in the patent. Floating strips (« doigts » in Figure 1) are mobile. Their position is controlled by a DC voltage VDC, as for MEMS, hence they can be shifted up or down, leading to a tunable transmission line capacitance, and hence tunable wave velocity and phase shift.

Description of the work

The PhD student will work both at IMEP-LAHC & CEA-LETI, in the MINATEC Center in Grenoble. The work will be divided in two main steps :
·         Design, realization and test of first millimeter-wave phase shifters for a proof-of-concept. The RF design and RF measurements will be carried out at IMEP-LAHC. The layout (taking into account mechanical stresses), realization and characterization will be carried out either at IMEP-LAHC or at CEA-LETI, depending on the technology that will be chosen.
·         Design, realization and test of antennas, power dividers and switches, in order to build a complete beam-forming front-end module based on an antenna-array. The power dividers will be realized thanks to a technology developed at IMEP-LAHC[6]. The switches will be developed in CEA-LETI with the same technology that will be used for the phase shifters.
·         Design, realization and test of the complete beam-forming system.

All the technological facilities, simulation tools and measurement systems that will be necessary for the work are available either at CEA-LETI or at IMEP-LAHC.

Contact:

Thesis supervisor : Philippe Ferrari, Professeur des Universités, Responsable de l’équipe RF & Millimétrique, IMEP-LAHC
Philippe Ferrari, Tel. : 00 33 4 56 52 95 68, philippe.ferrari@ujf-grenoble.fr

Thesis co-supervisor: Florence Podevin, Maître de Conférences, équipe RF & Millimétrique, IMEP-LAHC

Funding: from the French Ministry for High Education and Research

[3] G. Rehder, P. Ferrari, and P. Benech
“Ligne de transmission haute fréquence accordable”, Patent Publication number WO/2011/117532. Publication date: 29.09.2011.

[4] G. Rehder, T. Vo, and P. Ferrari
"Development of a slow-wave MEMS phase shifters on CMOS technology for millimeter wave frequencies", Microelectronic Engineering, Vol. 90, pp. 19-22, Feb. 2012.

[5] E. Carrasco, M. Barba, B. Reig, J. A. Encinar, P. L. Charvet,
“Demonstration of a Gathered Element for Reconfigurable-Beam Reflectarrays Based on Ohmic MEMS”, Proceedings of the fifth European Conference on Antenna and Propagation (EuCAP), 2011.

[6] A.-L. Franc, E. Pistono, N. Corrao, D. Gloria, and P. Ferrari,
"Compact high-Q, low-loss mmW transmission lines and power splitters in RF CMOS technology", Proc. IEEE International Microwave Symposium, IMS2011, Baltimore, USA, June 5-10, 2011.

Keys words: RF Devices & Systems
Laboratory:FMNT / IMEP-LAHC
CEA code:
Contact: ferrari@minatec.inpg.fr

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[PostDoc]

Reliability of the copper (Cu) direct bonding interconnects for 3D integration

Offer N°: 8380

Start date: 4 Jun 2012

Postdoc framework
Copper direct bonding is one of the most promising approaches for 3-D integration. The process is mature as shown in the work of Gueguen et al., Di Cioccio et al. and Taibi et al. for wafer to wafer (W2W) approach [1-3] but also in the case of a die to wafer one (D2W). However, its reliability is yet to be demonstrated even if the initial results from the PhD thesis of R. Taibi seem to be promising [4].

Work description
The purpose of this post-doc position will be first, to consolidate the results obtained by R. Taibi with the W2W approach and secondly, to study the reliability of the D2W approach from the electromigration and stress-induced voiding point of view.
The candidate will be responsible for all the reliability study, starting with the tests and the results’ analysis, failure analysis (optical, IR, SEM, FIB...), the determination of the degradation’s mechanisms.
The candidate will work with PhD students working on the copper direct bonding and its integration into devices. With its expertise, it will propose ways to improve the process

References

1.         Gueguen, P., et al. Copper direct bonding for 3D integration. in Interconnect Technology Conference, 2008. IITC 2008. International. 2008.
2.         Taibi, R., et al. Full characterization of Cu/Cu direct bonding for 3D integration. in Electronic Components and Technology Conference (ECTC), 2010 Proceedings 60th. 2010.
3.         Di Cioccio, L., et al., An Overview of Patterned Metal/Dielectric Surface Bonding: Mechanism, Alignment and Characterization. Journal of The Electrochemical Society, 2011. 158(6): p. 81-86.
4.         Taibi, R., et al., Investigation of Stress Induced Voiding and Electromigration Phenomena on Direct Copper Bonding Interconnects for 3D Integration, in 2011 IEEE International Electron Devices Meeting (IEDM). 2011: Washington, DC.

Host Institution

Direction/Département/Service/Laboratoire

DRT/DCOS/S3D

Postal address

CEA/GRENOBLE 17 rue des Martyrs38054 Grenoble CEDEX 9

Technical Supervisor
Stéphane MOREAU; phone: 04 38 78 06 36 ; email: stephane-nico.moreau@cea.fr
Léa DI CIOCCIO; phone: 04 38 78 37 62 ; email: lea.dicioccio@cea.fr

Keys words: Other
Laboratory:LETI / DCOS
CEA code:MOREAU_Stéphane
Contact: stephane-nico.moreau@cea.fr

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[Thesis]

Overview of the potentialities afforded by the SiGe 55nm technology dedicated for mm and sub-mm waves : slow-wave transmissions lines for baluns, power dividers and amplifiers matching

Offer N°: 8377

Start date: 1 Sep 2012

Required diploma : Master
Duration : 3 years
Required competences: Microwaves, electromagnetism, electronics, microelectronics

PhD subject
Overview of the potentialities afforded by the SiGe 55nm technology dedicated for mm and sub-mm waves : slow-wave transmissions lines for baluns, power dividers and amplifiers matching

Keywords
Millimeter waves CMOS circuits. 55nm BiCMOS advanced technology. High rate communications (6 Gbits/s – 60 GHz). Anti-collision radars (77-81 GHz). Imaging (94 GHz, 140 GHz).

Description
Context and aims
Nowadays, there is a strong need for advanced communication systems in the millimeter-wave (mmW) frequencies for applications like high-data rate telecommunications as fast video-streaming (from 57 GHz to 66 GHz in Europe), automotive radars (76 GHz to 81 GHz), RF-imaging (94 GHz, 140 GHz and above). In this context, systems integration is of major interest. However present systems are still limited by passive devices. Baluns, power dividers, matching networks suffer from big dimensions and substrate losses. As a solution, slow-wave coplanar waveguides (S-CPW) are highly interesting in terms of miniaturization. Moreover, integrated in a silicon die, they strongly reduce the losses due to the substrate[3].

As a consequence, S-CPW transmission lines show very high quality factors, at the state-of-the-art for integrated transmission lines. At the laboratory IMEP-LAHC, quality factors as high as 30 at 60 GHz are easily reached. In the framework of this PhD position, the work will consist to explore the potentialities of such transmission lines in the specific 55nm SiGe technology developed by ST Microelectronics. More precisely, this work takes part of a Catrene project named « RF2THz » headed by this company, aiming at covering very high frequencies for applications in the millimeter and sub-millimeter domains.

Once transmission lines model and characterization perfectly handled in the 55nm SiGe technology, the student will have to design passive circuits such as baluns (rat-race couplers, branch-lines couplers), power dividers or active circuits with amplifiers matched thanks to S-CPW stubs in order to maximise their operating gain.

Practical work
In a first time, student has to become familiar with slow-wave transmission lines principles, analytic model and 3D electromagnetic simulation. Simulating tools are available at the IMEP-LAHC laboratory, and the simulation environment has already been optimized. Student will be part of a team whose results in this domain has reached the state-of–the-art for 5 years now. During this 3 years period, he or she will closely focus on the exploration of the SiGe 55 nm technology for purely passive devices as well as for active circuits purpose. The student will design its proper layouts: various runs are enfaced during the PhD. Finally circuit characterization will takes place either at the IMEP-LAHC or directly at ST Microelectronics. The IMEP-LAHC has potential for high frequency vector network measurements: 300mm tip prober connected to a 2 ports 110GHz VNA, tip prober connected to a differential VNA (up to 67 Hz, which enables the W-HDMI components characterization). Some measurements campaign could take place directly at ST Microelectronics (4 ports VNA in the 56-94 GHz frequency range as an example).

Contact :
Thesis supervisor:Philippe Ferrari - Professor, Head of the RF & Millimeter group, IMEP-LAHC
Tel. : 00 33 4 56 52 95 68, philippe.ferrari@minatec.grenoble-inp.fr

Co-supervisor: Florence Podevin - Assistant professor, RF & Millimeter group, IMEP-LAHC

[3]. D. Kaddour, H. Issa, A.-L. Franc, N. Corrao, E. Pistono, F. Podevin, J.-M. Fournier, J.-M. Duchamp, and P. Ferrari, "High-Q Slow-Wave Coplanar Transmission lines on 0.35-µm CMOS Process", IEEE Microw. & Wireless Compon. Lett., Vol. 19, No. 9, pp. 542-544, Sep. 2009.