TY - JOUR
T1 - Metal- and oxide-related hydrogen-induced dipoles at the Pt/HfO2 interface
AU - Kolomiiets, N. M.
AU - Afanas'ev, V. V.
AU - Stesmans, A.
AU - Fadida, S.
AU - Eizenberg, M.
N1 - Publisher Copyright:
© 2017 Elsevier B.V.
PY - 2017/6/25
Y1 - 2017/6/25
N2 - Such technologically abundant agent as hydrogen has a strong effect on the metal/oxide interface energy barrier. Internal photoemission analysis of electron barrier height variations at Pt/HfO2 interfaces caused by annealing in hydrogen reveals the formation of a significant (≥ 0.4 eV) electrostatic dipole layer. The orientation of the H-induced dipole appears to be sensitive to the growth conditions and treatments, e.g., Hf precursor used in the atomic layer deposition (ALD) process: In the case of the HfCl4 precursor, annealing in H2 leads to barrier lowering, whereas the barrier becomes higher in samples grown by using tetrakis(dimethylamido)hafnium. These findings indicate that hydrogen may form dipoles of opposite orientation through two different mechanisms: The positive dipole is caused by H interaction with the metal surface, which can also be found at interfaces of Pt with other oxides such as SiO2 and Al2O3. By contrast, the sensitivity of the negative dipole formation to the HfO2 ALD chemistry suggests it to be related to a negatively charged bonded state of hydrogen in the near-interface oxide. Moreover, the formation of positive dipole is also observed after high temperature anneal in nitrogen suggesting the contribution of additional mechanisms of dipole formation.
AB - Such technologically abundant agent as hydrogen has a strong effect on the metal/oxide interface energy barrier. Internal photoemission analysis of electron barrier height variations at Pt/HfO2 interfaces caused by annealing in hydrogen reveals the formation of a significant (≥ 0.4 eV) electrostatic dipole layer. The orientation of the H-induced dipole appears to be sensitive to the growth conditions and treatments, e.g., Hf precursor used in the atomic layer deposition (ALD) process: In the case of the HfCl4 precursor, annealing in H2 leads to barrier lowering, whereas the barrier becomes higher in samples grown by using tetrakis(dimethylamido)hafnium. These findings indicate that hydrogen may form dipoles of opposite orientation through two different mechanisms: The positive dipole is caused by H interaction with the metal surface, which can also be found at interfaces of Pt with other oxides such as SiO2 and Al2O3. By contrast, the sensitivity of the negative dipole formation to the HfO2 ALD chemistry suggests it to be related to a negatively charged bonded state of hydrogen in the near-interface oxide. Moreover, the formation of positive dipole is also observed after high temperature anneal in nitrogen suggesting the contribution of additional mechanisms of dipole formation.
KW - Dipole
KW - Effective work function
KW - Interface barrier
KW - Internal photoemission
UR - http://www.scopus.com/inward/record.url?scp=85020012759&partnerID=8YFLogxK
U2 - 10.1016/j.mee.2017.05.051
DO - 10.1016/j.mee.2017.05.051
M3 - 文章
AN - SCOPUS:85020012759
SN - 0167-9317
VL - 178
SP - 304
EP - 307
JO - Microelectronic Engineering
JF - Microelectronic Engineering
ER -