All opportunities

Offers : 15

Simulation and electrical characterization of an innovative logic/memory CUBE for In-Memory-Computing

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Start date : 1 January 2020

offer n° PsD-DRT-20-0029

For integrated circuits to be able to leverage the future “data deluge” coming from the cloud and cyber-physical systems, the historical scaling of Complementary-Metal-Oxide-Semiconductor (CMOS) devices is no longer the corner stone. At system-level, computing performance is now strongly power-limited and the main part of this power budget is consumed by data transfers between logic and memory circuit blocks in widespread Von-Neumann design architectures. An emerging computing paradigm solution overcoming this “memory wall” consists in processing the information in-situ, owing to In-Memory-Computing (IMC).

However, today’s existing memory technologies are ineffective to In-Memory compute billions of data items. Things will change with the emergence of three key enabling technologies, under development at CEA-LETI: non-volatile resistive memory, new energy-efficient nanowire transistors and 3D-monolithic integration. At LETI, we will leverage the aforementioned emerging technologies towards a functionality-enhanced system with a tight entangling of logic and memory.

The post-doc will perform electrical characterizations of CMOS transistors and Resistive RAMs in order to calibrate models and run TCAD/spice simulations to drive the technology developments and enable the circuit designs.

  • Keywords : Engineering sciences, Technological challenges, Electronics and microelectronics - Optoelectronics, New computing paradigms, circuits and technologies, incl. quantum, DCOS, Leti
  • Laboratory : DCOS / Leti
  • CEA code : PsD-DRT-20-0029
  • Contact : francois.andrieu@cea.fr

Design of innovative time-domain microphone readout using Injection Locked Oscillators

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Start date : 1 January 2020

offer n° PsD-DRT-20-0023

Nowadays, Voice Activity Detection is a hot research topic. This application needs the design of high linearity, high dynamic ( > 100 dBSpl) and low noise (< 25 dBSpl) microphones putting stringent requirement on both the transducer and the readout electonics. State of the art microphone readouts are based on a classical amplifier and sigma delta conversion. They fulfill the needs in term of dynamic and noise but at the expense of a high power consumption (1 mW) not compliant with mobile applications.

CEA-LETI is currently working on an innovative transducer design that fulfills the needs in terms of dynamic and noise. To go along with the transducer development, CEA-LETI is searching for a PostDoc whose mission will be to study an Ultra Low Power architecture of readout circuits working in the time-domain and based on Injection Locked Oscillators. The post doc work will consist in an architecture study and its evaluation in term of expected performances. In a second time an optimized chip should be designed and fabricated. Evaluation of the solution will be made by a thorough measurement of the test chip.

  • Keywords : Engineering sciences, Technological challenges, Cyber physical systems - sensors and actuators, Electronics and microelectronics - Optoelectronics, DACLE, Leti
  • Laboratory : DACLE / Leti
  • CEA code : PsD-DRT-20-0023
  • Contact : franck.badets@cea.fr

Nano-optomechanical silicon accelerometer for high performance applications

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Start date : 1 June 2020

offer n° PsD-DRT-20-0035

Inertial sensors (accelerometers and gyrometers) are at the heart of a large number of consumer-and low-cost applications such as smartphones and tablets, but also higher added value, higher-performance applications such as navigation for autonomous vehicles, aeronautics or space. Silicon microsystems (MEMS) are today a very mature technology and several millions are sold each year. However, they are today unable to address high-performance applications.

LETI has been pioneering the development of optomechanical sensors “on-chip”: light is guided in thin silicon layers in a similar way to photonics techniques. This light interacts with an object in motion such as a mechanical resonator or a seismic mass. This displacement modulates the intensity of the measured light, which allows the determination of the object’s acceleration. This technology was developed in the 2000s in fundamental research, and in particular enabled gravitational wave detectors. LETI is developing this technology on-chip at the nanoscale, with displacement sensitivities several orders of magnitude better than electrical transductions.

First optomechanical accelerometers were designed and fabricated in LETI’s quasi-industrial clean rooms for initial characterization tests. The hired fellow with have to become familiar with these devices, to confirm the first optical results, and then most importantly to assess their performances under acceleration: a test setup will have to be realized for this purpose. She or he will have to provide feedback on the modeling and the design from the measurements in order to ensure the comprehension of all phenomena at play. Finally, the postdoctoral fellow will have to propose new designs aimed at the expected high performances. These devices will be fabricated by the clean room, tested by the fellow and and compared to the expected performance.

  • Keywords : Technological challenges, Cyber physical systems - sensors and actuators, DCOS, Leti
  • Laboratory : DCOS / Leti
  • CEA code : PsD-DRT-20-0035
  • Contact : sebastien.hentz@cea.fr

Inductors for quantum reflectometry

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Start date : 1 April 2020

offer n° PsD-DRT-20-0039

Quantum computing is nowadays a strong field of research at CEA-LETI and in numerous institutes and companies around the world. Reflectometry is one of the major avenues envisaged for Qubits reading. Reflectometry and frequency multiplexing techniques requires many small resonators that must be positioned as close to the quantum chip as possible. First demonstrations performed with discrete inductors showed limitations in terms of size and coupling.

Large-scale passives component integration technologies mastered at CEA-LETI can meet these dimensional constraints. Especially, CEA-LETI is positioned at the highest level of the state of the art in magnetic inductors on silicon, with record inductance densities (> 3 000 nH/mm²). First measurements have already validated the operation of the technology at very low temperature. We now have to demonstrate the feasibility of an inductive interposer dedicated to Qubits reading by leveraging high inductance densities.

The student will perform the accurate RF characterization of our magnetic inductors at cryogenic temperature. He will analyze the obtained results to describe the electrical and magnetic behaviour of the components. The bibliographic analysis and the studies already carried out will enable him to define a new technological stack combining the advantages of magnetic materials and superconductors. He will propose suitable designs to realize high quality factor inductors and an inductive interposer for Quantum reflectometry.

  • Keywords : Technological challenges, New computing paradigms, circuits and technologies, incl. quantum, DCOS, Leti
  • Laboratory : DCOS / Leti
  • CEA code : PsD-DRT-20-0039
  • Contact : jean-philippe.michel@cea.fr

Measurement of active cell nematics by lensless microscopy

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Start date : 1 March 2020

offer n° PsD-DRT-20-0059

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 of the post-doc is to extend the analysis of the datasets produced by lens-free video microscopy. The post-doc will assist our partner in conducting the experimentations and will develop the necessary algorithms to reconstruct the images of the cell culture in different conditions. In particular, we will challenge the holographic reconstruction algorithms with the possibility to quantify the optical path difference (i.e. the refractive index multiplied by the thickness). Existing algorithms allow to quantify isolated cells. They will be further developed and assessed to quantify the formation of cell stacking in all three dimensions. These algorithms will have no Z-sectioning ability as e.g. confocal microscopy, only the optical path thickness will be measured.

We are looking people who have completed a PhD in image processing and/or deep learning with skills in the field of microscopy applied to biology.

  • Keywords : Engineering sciences, Technological challenges, Health and environment technologies, medical devices, Instrumentation, DTBS, Leti
  • Laboratory : DTBS / Leti
  • CEA code : PsD-DRT-20-0059
  • Contact : cedric.allier@cea.fr
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