Development of innovative etching processes for the integration of ferroelectric materials in non-volatile memories

Published : 1 January 2023

Today, memories are once again a priority for two reasons: data production is growing exponentially. Data storage and transfer consumes up to 90% of the energy in computing systems. Non-volatile memories, which retain information when not powered, are needed to limit energy consumption. Ferroelectric memories (FeRAM or FRAM) are one of the emerging non-volatile memory technologies with great potential.

The ferroelectric property of (Hf, Zr)O2 was demonstrated in 2011, marking the beginning of research into innovative ferroelectric memories. The compatibility of HZO (hafnium zinc oxide) with CMOS and the very low power consumption of these memories explain in part the current strong interest in this field.

Plasma etching of the Metal/Ferroelectric/Metal (MFM) capacitor is a key step. The objective of the proposed topic is to develop processes for etching and cleaning the memory stack while studying the interaction of the etching plasma and cleaning chemistries with the HZO film. In addition, the impact of the developed processes on the HZO will be correlated to the variations of the electrical characteristics of the capacitor. Finally, the future PhD student will focus on optimising or even proposing an innovative etching process that guarantees the expected ferroelectric performances.

You will be based at the CEA-LETI Etching Laboratory and will benefit from the process and characterization equipment of the Nanotechnology platform. The scientific and industrial interest of the subject guarantees you a valorization of your work during international communications.

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