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Sharp-Switching Z2-FET Device: Novel applications, Scaling, Reliability and Variability
Published : 24 May 2017
PhD Thesis : Registration DEADLINE on June 13th, 2017
Sharp-Switching Z2-FET Device: Novel applications, Scaling, Reliability and Variability
Thesis co-advisors: Maryline Bawedin, IMEP-LAHC,
Joris Lacord, CEA-LETI,
Jacques Cluzel, CEA-LETI
Sorin Cristoloveanu, CNRS, IMEP-LAHC
Contacts: Maryline Bawedin, IMEP-LAHC,
Joris Lacord, CEA-LETI,
External cooperations: Univs. of Glasgow, Fudan (China), San Diego, Brown (USA) and Granada, STMicroelectronics.
The Z2-FET has recently been conceived in Grenoble and fabricated with FD-SOI technology by CEA-LETI and STMicroelectronics. The device is a forward-biased PIN diode, where the current is blocked by energy barriers induced by the front and back gates. A virtual PNPN thyristor with electrostatic doping is emulated. A positive feedback mechanism triggers the current on, leading to an extremely sharp switch (< 1mV/decade) from low OFF to high ON current, even for operation at ~1 V.
Recent studies have been focused on applications related to capacitorless floating-body memory (1T-DRAM) and protection against electrostatic discharge (ESD). The unrivalled performance of Z2-FETs can also be utilized for other novel applications. The research program is three-fold.
1 – Innovative applications. The goal is to design simple logic circuits that take advantage of the vertical switch between OFF and ON states in order to increase the speed and reduce the power. A single-transistor SRAM will also be explored. Finally, the feasibility of Z2-FET-based sensors (chemical, photo, magnetic) will be investigated. The implementation of the device in nanowires will be envisaged.
2 – Device scaling and variability. The minimum length, compatible with state-of-the-art FD-SOI technology, will be determined. The impact of fluctuations in size, film thickness and carrier lifetime will be studied.
3 – Reliability. Despite the advantage of low-voltage operation, carrier injection into the gate dielectric can still cause aging effects. Systematic experiments and TCAD simulations will be performed. This segment of research will also include low-frequency noise measurements. The conclusions of reliability and variability studies will directly apply to the optimization of memories and ESD devices.
The aim of this PhD project is ambitious at the fundamental science level and application-oriented. The research will require strong interaction between various fields of expertise: physics of semiconductor devices, electrical characterization, TCAD simulations and physics-based modeling. Candidates with previous experience in these fields will be highly appreciated. Scientific talent and strong motivation are key criteria of selection. The expertise gained during the PhD will lead not only to numerous publications but also to a successful professional career.
Related publications from IMEP:
H.El DIRANI, K. LEE, M. S. PARIHAR, J. LACORD, S. MARTINIE, J.-C. BARBE, X. MESCOT, P. FONTENEAU, P. GALY, F. GAMIZ, Y. TAUR, S. CRISTOLOVEANU, M. BAWEDIN
Ultra Low-Power 1T-DRAM in FDSOI Technology, 20th Conference on “Insulating Films on Semiconductors”, 2017, Germany.
J. WAN, C. LE ROYER, A. ZASLAVSKY, S. CRISTOLOVEANU
A compact capacitor-less high-speed DRAM using field effect-controlled charge regeneration.
IEEE Electron Device Letts., 33, n◦ 2, 179{181 (2012)
M. BAWEDIN, S. CRISTOLOVEANU, D. FLANDRE
A capacitor-less 1T-DRAM on SOI based on double gate operation.
IEEE Electron Device Letts., 29, n± 7, 795–798 (2008)
J. WAN, S. CRISTOLOVEANU, C. LE ROYER, A. ZASLAVSKY
A feedback silicon-on-insulator steep switching device with gate-controlled carrier injection.
Solid-State Electronics, 76, 109{111 (2012)
J. WAN, A. ZASLAVSKY, C. LE ROYER, S. CRISTOLOVEANU
A systematic study of the sharp-switching Z2-FET device : from mechanism to modeling and
compact memory applications.
Solid-State Electronics, 90, 2{11 (2013)
H. EL DIRANI, Y. SOLARO, P. FONTENEAU, C.-A. LEGRAND, D. MARIN-CUDRAZ,
D. GOLANSKI, P. FERRARI, S. CRISTOLOVEANU
A band-modulation device in advanced FDSOI technology : sharp switching characteristics.
Solid-State Electronics, 125, 103{110 (2016)
