Berlin 2018 – wissenschaftliches Programm

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DS: Fachverband Dünne Schichten

DS 5: Layer Deposition (ALD, MBE, Sputtering, ...)

DS 5.1: Vortrag

Montag, 12. März 2018, 11:45–12:00, H 0111

Atomic Layer Deposition of Titanium Nitride Thin Films for Plasmonic Applications — •Gül Dogan, Umut T. Sanli, Gisela Schütz, and Kahraman Keskinbora — MPI for Intelligent Systems, Stuttgart

Titanium Nitride (TiN) emerged as an alternative to gold as a material for refractory plasmonics, mainly due to their similar optical responses in the visible and near-infrared regions. Atomic Layer Deposition (ALD) offers highly conformal coatings over complex geometries, accurate thickness, atomic smooth interfaces and composition control. Here, we deposited TiN thin films at 350 °C by a plasma-enhanced (PE)-ALD, using TiCl4 and N2-H2 as co-reactants. The deposition rate was 0.03 nm/cycle. The prepared polycrystalline films exhibited a strong (200) preferred orientation. The XPS analysis indicated that the Cl impurity concentration was ~4 at. % and the atomic ratio of Ti to N was ~1:1. A low resistivity of 290 uohm.cm was measured by Four Point Probe (FPP). The optical-resistivity values were determined via Spectroscopic Ellipsometry using a Drude-Lorentz model, which were in agreement with FPP measurements, for ~10 nm grain size. When the grain size was <10 nm, large deviations were observed between optical and electrical resistivity measurements, which was attributed to electron scattering at grain boundaries. Low electrical resistivity in combination with a high carrier concentration and carrier mobility are two important parameters for plasmonic applications. Furthermore, a discrepancy between optical and electrical measurements is a reliable indicator of grain boundary scattering.