Friday, November 9, 2018

Imec to present scaled Superduper High-k Ruthenium/Strontium titanate capacitor at IEDM

Here is another interesting IEDM 2018 paper from Imec. It is a classical paper obn DRAM capacitor scaling featuring the almost impossible Superduper High-k Ruthenium/Strontium titanate capacitor! It is an ALD integration, the patterning the capacitor everything - no need to involve anyone else - it is up to the Litho and ALD people to get the job done.

Paper #2.7, "High-Performance (EOT<0.4nm, Jg~10-7 A/cm2) ALD-Deposited Ru/SrTiO3 Stack for Next-Generation DRAM Pillar Capacitor," M. Popovici et al, Imec)

I have not seen the abstract but it has been reviewed by CDRInfo (see paragraph below) and I am sure there will be more details available soon (LINK):

"Scaling DRAM Technology To 16nm And Beyond: DRAM memory technology is used in virtually all electronic systems because of its speed and density. DRAM memory comprises arrays of capacitor-transistor pairs which store data as electrical charge in the capacitor; the presence of charge indicates "1" and its absence "0." Manipulation of these digits is the basis of computer programming. It’s difficult to scale DRAM to the 16nm generation and beyond because of space limitations which make it hard to pack enough capacitance within the pitch. Imec researchers used an atomic layer deposition (ALD) process to pattern and build a novel 11nm pillar-shaped capacitor using new dielectric materials (SrTiO3, or STO). By tailoring the material properties of the capacitor and the SrRuO3 (SRO) epitaxial template on which it was grown, the researchers achieved a very high dielectric constant (k~118) and low electrical leakage (10-7 A/cm2 at ±1V). This means that pillar-shaped capacitors can be used instead of existing cup-shaped capacitors, without paying too great a penalty in terms of reduced data-storage capability. These results make the STO capacitors suitable for continued scaling for 16nm and smaller DRAMs."
Construction work at Imec, Leuven, June 2013. The tower looks a bit like a DRAM Capacitor but somehow I do not think that the architect know that and I bet they were working on Ru/STO ALD well before that!