In order to explore solutions to overcome the scaling limitations of conventional
Flash memory cells, IMEC
has started new research activities on resistive RAM (RRAM) cells. With these
activities, IMEC answers the needs of today's major memory companies.
Resistive switching memories are based on materials whose resistivity can be
electrically switched between high and low conductive states. RRAM is becoming
of interest for future scaled memories because of their superior intrinsic scaling
characteristics compared to the charge-based Flash devices, and potentially
small cell size (enabling dense crossbar RRAM arrays using vertical diode selecting
elements). RRAM is seen as a potential candidate to replace conventional Flash
memory and hence to push NVM technology towards the (sub-)22nm technology node.
For making such RRAM, different concepts and materials are proposed. IMEC's
research activities on RRAM mainly focus on investigating the switching behavior
of the RRAM cell concept that uses metal oxides as a switching element, and
on demonstrating its scaling capability down to 25nm. The study concentrates
on three main topics, being RRAM stack optimization (including the choice of
top and bottom electrode and of the metal oxide), RRAM cell scaling and RRAM
integration in a crossbar RRAM array.
These new research activities are part of IMEC's Emerging Memory program
that provides innovative non-volatile memory (NVM) technology, concepts and
solutions for the 32nm generation and below. Besides activities on RRAM, IMEC
also started to explore floating body cells (FBCs) for embedded and stand-alone
DRAM and SRAM replacement. With these activities, IMEC answers the needs of
today's major memory industry players. IMEC's vast background in
NVM memory physics, reliability, modeling as well as process integration in
state-of-the-art platforms and design and test issues, allows for these new
concepts to be explored in a fast and cost-effective way.