MNOS stack for reliable, low optical loss, Cu based CMOS plasmonic devices.
We study the electro optical properties of a Metal-Nitride-Oxide-Silicon (MNOS) stack for a use in CMOS compatible plasmonic active devices. We show that the insertion of an ultrathin stoichiometric Si(3)N(4) layer in a MOS stack lead to an increase in the electrical reliability of a copper gate MNOS capacitance from 50 to 95% thanks to a diffusion barrier effect, while preserving the low optical losses brought by the use of copper as the plasmon supporting metal. An experimental investigation is undertaken at a wafer scale using some CMOS standard processes of the LETI foundry. Optical transmission measurments conducted in a MNOS channel waveguide configuration coupled to standard silicon photonics circuitry confirms the very low optical losses (0.39 dB.μm(-1)), in good agreement with predictions using ellipsometric optical constants of Cu.
CEA, LETI, Minatec Campus, 17 rue des martyrs, F-38042 Grenoble, France.
Alexandros
A
Emboras
Adel
A
Najar
Siddharth
S
Nambiar
Philippe
P
Grosse
Emmanuel
E
Augendre
Charles
C
Leroux
Barbara
B
de Salvo
Roch Espiau
RE
de Lamaestre
D003300:Copper / Q000737:chemistry*; D004735:Energy Transfer; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008027:Light; D012031:Refractometry / Q000295:instrumentation*; D012542:Scattering, Radiation; D020349:Surface Plasmon Resonance / Q000295:instrumentation*; D014173:Transistors, Electronic
D003300:Copper