TY - JOUR
T1 - Chemical Interaction of Hydrogen Radicals (H*) with Transition Metal Nitrides
AU - Rehman, Abdul
AU - van de Kruijs, Robbert W.E.
AU - van den Beld, Wesley T.E.
AU - Sturm, Jacobus M.
AU - Ackermann, Marcelo
N1 - Funding Information:
This work has been carried out in the frame of the Industrial Partnership Program “X-tools,” project no. 741.018.301, funded by the Netherlands Organization for Scientific Research, ASML, Carl Zeiss SMT, and Malvern Panalytical. We acknowledge the support of the Industrial Focus Group XUV Optics at the MESA+ Institute for Nanotechnology at the University of Twente. The authors would also like to thank Dr. Parikshit Phadke (University of Twente), Prof. Jörg Meyer (Leiden University), and Dr. Jonathon Cottom (Leiden University) for their insightful scientific discussions.
Publisher Copyright:
© 2023 The Authors. Published by American Chemical Society.
PY - 2023/9/14
Y1 - 2023/9/14
N2 - Transition metal nitrides (TMNs) are reported as protective coatings in reactive hydrogen environments. Although the permeation of H2 through TMN coatings is well reported, their reducibility in H* environments is less investigated. In this work, we categorize the interaction of H* with ambient exposed TiN, ZrN, HfN, VN, NbN, and TaN thin films at 700 °C into three classes. We find that in TiN and VN samples, H*-induced reduction was limited to the surface (≈ top 2 nm). Significant denitridation was observed in ZrN and HfN samples beneath the surface, along with an increase in the transition metal oxide (TMOx) fraction. Denitridation was observed in NbN and TaN samples as well, but the increase in the TMOx content was less than for ZrN and HfN. We propose a model in three steps: hydrogenation, formation of volatile species, and diffusion of subsurface atoms to the surface. We show that the interaction of H* with TiN, ZrN, HfN, VN, NbN, and TaN with partially oxidized surfaces can be explained using the preferred hydrogenation pathway (based on the work functions) and the thermodynamic driver for forming volatile species (NH3 and H2O; based on the change in Gibbs free energy).
AB - Transition metal nitrides (TMNs) are reported as protective coatings in reactive hydrogen environments. Although the permeation of H2 through TMN coatings is well reported, their reducibility in H* environments is less investigated. In this work, we categorize the interaction of H* with ambient exposed TiN, ZrN, HfN, VN, NbN, and TaN thin films at 700 °C into three classes. We find that in TiN and VN samples, H*-induced reduction was limited to the surface (≈ top 2 nm). Significant denitridation was observed in ZrN and HfN samples beneath the surface, along with an increase in the transition metal oxide (TMOx) fraction. Denitridation was observed in NbN and TaN samples as well, but the increase in the TMOx content was less than for ZrN and HfN. We propose a model in three steps: hydrogenation, formation of volatile species, and diffusion of subsurface atoms to the surface. We show that the interaction of H* with TiN, ZrN, HfN, VN, NbN, and TaN with partially oxidized surfaces can be explained using the preferred hydrogenation pathway (based on the work functions) and the thermodynamic driver for forming volatile species (NH3 and H2O; based on the change in Gibbs free energy).
KW - UT-Hybrid-D
U2 - 10.1021/acs.jpcc.3c04490
DO - 10.1021/acs.jpcc.3c04490
M3 - Article
SN - 1932-7447
VL - 127
SP - 17770
EP - 17780
JO - The Journal of physical chemistry C
JF - The Journal of physical chemistry C
IS - 36
ER -