Nanomaterials & integration

Oxide and chalcogenide materials

Contact: Christophe Vallée, Patrice Gonon

The first one is dedicated to oxide and chalcogenide materials for resistive memories, MOS transistors and MIM capacitors.
Concerning memory applications, we focused on low operating voltage memory with a 3D stacking capability. Chalcogenide (GeS, GeSbTe, GeTe…) and oxide materials (HfO2, TiO2…) based resistive memories offer these potentials. Plasma Enhanced CVD process is developed for the conformal deposition of Phase Change Materials (PCM) such as GeTe and GeSbTe, with specific doping. In situ characterization of the plasma (by Optical Emission Spectroscopy) and the thin film (XPS, via vacuum transfer) are systematically carried out.
MIM capacitors (for DRAM, decoupling applications, RF, VCO, ADC) objective is to obtain high density capacitance (>10 nF/microns²), with a low leakage current (<µA/cm ²) with a constant capacitance. A potential solution is to increase geometrically the electrodes surface by nanostructured capacitors using PEALD for oxide conformal deposition.
Finally, the breakdown mechanisms of gate oxides for MOS transistors (HfSiON/SiON, SiON, SiO2…) are studied by conductive AFM under ultra-high vacuum in cooperation with STMicroelectronics and CEA-Léti.

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Since one year, a new axis is launched on the development of III-V compounds integration on a Si platform. A 300 mm MOCVD tool is installed, in collaboration with CEA-Leti, in the Leti clean room. We will explore the potentiality of arsenic and phosphorous based compounds epitaxially grown on a Si substrate for nanoelectronic, photonic and photovoltaic applications.

Equipments: – 200 mm PE-MOCVD deposition of GST materials and 300 mm PE-MOCVD for metal gate
– Electrical characterization of Resistive-RAM elementary structures
– Environmental and UHV electrical based-AFM methods
– 100 mm CVD for Si and Ge NWs shared with CEA-INAC
– 300 mm MOCVD for III-As and III-P epitaxy
– 200 mm RTP furnace
– 200 mm PVD