Anomalous positive flatband voltage shifts in metal gate stacks containing rare-earth oxide capping layers
Type
ArticleAuthors
Caraveo-Frescas, Jesus AlfonsoHedhili, Mohamed N.

Wang, H.
Schwingenschlögl, Udo

Alshareef, Husam N.

KAUST Department
Advanced Nanofabrication, Imaging and Characterization Core LabComputational Physics and Materials Science (CPMS)
Functional Nanomaterials and Devices Research Group
Imaging and Characterization Core Lab
Material Science and Engineering Program
Physical Science and Engineering (PSE) Division
Date
2012-03-10Online Publication Date
2012-03-10Print Publication Date
2012-03-05Permanent link to this record
http://hdl.handle.net/10754/552880
Metadata
Show full item recordAbstract
It is shown that the well-known negative flatband voltage (VFB) shift, induced by rare-earth oxide capping in metal gate stacks, can be completely reversed in the absence of the silicon overlayer. Using TaN metal gates and Gd2O3-doped dielectric, we measure a ∼350 mV negative shift with the Si overlayer present and a ∼110 mV positive shift with the Si overlayer removed. This effect is correlated to a positive change in the average electrostatic potential at the TaN/dielectric interface which originates from an interfacial dipole. The dipole is created by the replacement of interfacial oxygen atoms in the HfO2 lattice with nitrogen atoms from TaN.Citation
Anomalous positive flatband voltage shifts in metal gate stacks containing rare-earth oxide capping layers 2012, 100 (10):102111 Applied Physics LettersPublisher
AIP PublishingJournal
Applied Physics Lettersae974a485f413a2113503eed53cd6c53
10.1063/1.3692580