|[March 11, 2014]
Leti Demonstrates Ultra-Scaled Self-Aligned Split-Gate Memory Cell with 16nm Gate Length
GRENOBLE, France --(Business Wire)--
CEA-Leti announced today it has fabricated ultra-scaled split-gate
memories with gate length of 16nm, and demonstrated their functionality,
showing good writing and erasing performances with memory windows over
The devices provide several benefits especially for contactless memory
applications, such as enlargement of the memory window and increased
functionality. Also because of an optimised fabrication step, the
devices allow better control of spacer memory gate shape and length.
Split-gate flash memories are made of two transistors: an access
transistor and a memory transistor with a charge-trapping layer
(nitride, Si nanocrystals etc.). Split-gate architectures use a
low-access voltage and minimize drain current during programming, which
leads to a decrease of the programming power compared to standard
one-transistor NOR memories. Because programming energy decreases when
memory gate length decreases, ultra-scaling is particularly relevant for
Memory gate has been reduced down to 16nm thanks to a poly-Si spacer
formed on the sidewall of the select transistor. This approach avoids
costly lithography steps during fabrication and solves misalignment
issues, which are responsible for a strong variation of the electrical
performances, such as the memory window.
The main challenges of this self-aligned technology concern the precise
control of the spacer memory gate shape and of the memory gate length.
Spacer gate has to fulfil two difficult requirements: being as flat as
possible in order to get a silicidation surface as large as possible
while insuring a functional contact, and getting a steep edge in order
to control the drain-junction doping.
By creating innovation and transferring it to industry, Leti is the
bridge between basic research and production of micro- and
nanotechnologies that improve the lives of people around the world.
Backed by its portfolio of 2,200 patents, Leti partners with large
industrials, SMEs and startups to tailor advanced solutions that
strengthen their competitive positions. It has launched more than 50
startups. Its 8,000m� of new-generation cleanroom space feature 200mm
and 300mm wafer processing of micro and nano solutions for applications
ranging from space to smart devices. Visit www.leti.fr
for more information.
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