Ultra-thin HfOxNy gate dielectric films were deposited by pulse-mode metalorganic chemical vapor deposition (MOCVD) with [(C2H5)2Hf (TDEAH) and either NO or O 2 as oxidants. Nitrogen incorporation was studied by jc-ray photoelectron spectroscopy (XPS) and spatially-resolved elemental profiles were obtained by scanning transmission electron microscopy (STEM) coupled with electron energy loss spectroscopy (EELS) and energy dispersive x-ray spectroscopy (EDS). The results indicate that nitrogen is incorporated throughout the high-k film with a higher concentration in the interface layer between the deposited layer and the Si(100) substrate. The concentration of nitrogen is increased in both layers by using NO instead of O2 as the oxidant. The N in the deposited and interface layers can be replaced by oxygen during oxygen ambient annealing at temperatures above 500°C. Films with 8 at.% nitrogen remain amorphous following vacuum annealing at temperatures up to 800 °C. By encapsulating vacuum-annealed films with amorphous Si from an e-beam evaporator prior to removal from the cluster tool, it was possible to reduce the thickness of the interface layer upon air exposure to the 0.5 nm range.
|Number of pages||6|
|Journal||Materials Research Society Symposium Proceedings|
|State||Published - 1 Dec 2004|
|Event||Integration of Advanced Micro- and Nanoelectronic Devices - Critical Issues and Solutions - San Francisco, CA, United States|
Duration: 13 Apr 2004 → 16 Apr 2004