In MilliTech prohject we achieved a number of excellent results in terms of advanced technological and functional proof of concepts for steep slope 2D devices and hybridization with phase change technologies for low power digital, analog and sensing applications.
We have developed novel Band-to-Band-Tunneling devices based on 2D/2D semiconducting structures, such as WSe2/SnSe2 Vertical Tunnel FETs and have integrated on the same technology platform WSe2 MOSFETs, with capability of steep-slope swing below 60mV/decade and voltage operation below 0.3V. By using negative capacitance (NC) as technology boosters we have created novel functionalities and improved the performance of devices, creating NC 2/2D Tunnel FETs and NC 2D MOSFETs with excellent low power capabilities. We have integrated and optimized Si-doped HfO2 as ferroelectric in the gate stacks of our 2D device platform to create opportunities for both negative capacitance devices and memristive functions.
We have developed the integration of 2D semiconductors with Metal-Insulator-Transition (MIT) materials such as VO2 to realize a hybrid heterostructure technological platform with hysteric abrupt switches with low power applications ranging from low power steep slope to neuromorphic circuits.
The MIT devices served to design and demonstrate new classes of low power optical and Terahertz sensing functions, having the capability to generated spiking signals with the frequency modulated by power/intensity of input waves/signals. We have developed the analytical modeling with physical parameters of these new classes of MIT devices enabling both optimizations and co-design with advanced CMOS platform. In the biosensing domain, we have achieved experimental prof of concepts for negative capacitance sensors and we have explored the sensing of other biomarkers, beyond PH and ions, like hormones. The work has been very experimental and technological in its nature but we devised the necessary understanding of device physics for 2D semiconducting and MIT device underneath physics, enabling optimization path for various types of applications.
The MilliTech team members participated and disseminated their results to many international events such as in IEEE International Electron Devices Meeting editions, from 2017 to 2020, the leading conference in nanoelectronics, where we presented the first hybrid VO2/MOS2 junction transistor, novel ferro-functionalization of gate stacks for biosensing (work included in the very selective conference press kit), and where we presented a keynote talk showing the important role of the technology develop in the project for Edge Artificial Intelligence applications. Other conferences have been attended such as ESSDERC/ESSCIRC, Transducers, MRS, IRMMW-THz and SPIE Sensors. Collaborations with other EU projects have been established. We have also update our Master and Doctoral Courses at Ecole Polytechnique Fédérale de Lausanne based on the results of the Milli-Tech project.
Overall, the project produced more that 40 journals and conference papers and supported the career of 7 PhDs and 2 Post-doctoral fellows in academic research and industry.
