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Assessment of Energy Barriers Between ZrCuAlNi Amorphous Metal and Atomic Layer Deposition Insulators Using Internal Photoemission Spectroscopy
Author(s) -
Jenkins Melanie A.,
Klarr Tyler,
Austin Dustin Z.,
Li Wei,
Nguyen Nhan V.,
Conley John F.
Publication year - 2018
Publication title -
physica status solidi (rrl) – rapid research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.786
H-Index - 68
eISSN - 1862-6270
pISSN - 1862-6254
DOI - 10.1002/pssr.201700437
Subject(s) - work function , atomic layer deposition , materials science , amorphous solid , photoemission spectroscopy , insulator (electricity) , vacuum level , metal , x ray photoelectron spectroscopy , dipole , spectroscopy , barrier layer , analytical chemistry (journal) , layer (electronics) , nanotechnology , optoelectronics , chemistry , crystallography , nuclear magnetic resonance , physics , metallurgy , organic chemistry , quantum mechanics , chromatography
The energy barrier heights between an ultra‐smooth amorphous metal electrode, ZrCuAlNi, and several atomic layer deposited (ALD) insulators are measured using internal photoemission (IPE) spectroscopy. ZrCuAlNi–insulator barriers are characterized within metal–insulator–metal (MIM) stacks with Al top contacts and results are compared with the Al/insulator barrier heights. The measured barrier heights at the ZrCuAlNi interface are found to be 3.3, 3.2, 3.0, and 2.2 eV for SiO 2 , Al 2 O 3 , HfO 2 , and ZrO 2 , respectively. This barrier height trend is consistent with the electron affinity of the respective oxides. However, barriers for SiO 2 and Al 2 O 3 are smaller than that ideally expected based on the reported vacuum work function of ZrCuAlNi, indicating a smaller ZrCuAlNi effective work function in these device structures. The measured Al barrier height results confirm previous reports of a negative dipole at the Al–ALD insulator interface.