Sub-Nanometer Interfacial Oxides on Highly Oriented Pyrolytic Graphite and Carbon Nanotubes Enabled by Lateral Oxide Growth.

Autor:	Zhang Z; Materials Science and Engineering Program, Department of Mechanical Engineering, University of California, La Jolla, San Diego, California 92093, United States., Passlack M; Corporate Research, Taiwan Semiconductor Manufacturing Company, San Jose, California 95134, United States., Pitner G; Corporate Research, Taiwan Semiconductor Manufacturing Company, San Jose, California 95134, United States., Kuo CH; Materials Science and Engineering Program, Department of Mechanical Engineering, University of California, La Jolla, San Diego, California 92093, United States., Ueda ST; Materials Science and Engineering Program, Department of Mechanical Engineering, University of California, La Jolla, San Diego, California 92093, United States., Huang J; Materials Science and Engineering Program, Department of Mechanical Engineering, University of California, La Jolla, San Diego, California 92093, United States., Kashyap H; Materials Science and Engineering Program, Department of Mechanical Engineering, University of California, La Jolla, San Diego, California 92093, United States., Wang V; Materials Science and Engineering Program, Department of Mechanical Engineering, University of California, La Jolla, San Diego, California 92093, United States., Spiegelman J; Department of Chemistry and Biochemistry, University of California, La Jolla, San Diego, California 92093, United States., Lam KT; Corporate Research, Taiwan Semiconductor Manufacturing Company, Hsinchu 30078, Taiwan., Liang YC; Corporate Research, Taiwan Semiconductor Manufacturing Company, Hsinchu 30078, Taiwan., Liew SL; Corporate Research, Taiwan Semiconductor Manufacturing Company, Hsinchu 30078, Taiwan., Hsu CF; Corporate Research, Taiwan Semiconductor Manufacturing Company, Hsinchu 30078, Taiwan., Kummel AC; Department of Chemistry and Biochemistry, University of California, La Jolla, San Diego, California 92093, United States., Bandaru P; Materials Science and Engineering Program, Department of Mechanical Engineering, University of California, La Jolla, San Diego, California 92093, United States.
Jazyk:	angličtina
Zdroj:	ACS applied materials & interfaces [ACS Appl Mater Interfaces] 2022 Mar 09; Vol. 14 (9), pp. 11873-11882. Date of Electronic Publication: 2022 Feb 22.
DOI:	10.1021/acsami.1c21743
Abstrakt:	A new generation of compact and high-speed electronic devices, based on carbon, would be enabled through the development of robust gate oxides with sub-nanometer effective oxide thickness (EOT) on carbon nanotubes or graphene nanoribbons. However, to date, the lack of dangling bonds on sp 2 oriented graphene sheets has limited the high precursor nucleation density enabling atomic layer deposition of sub-1 nm EOT gate oxides. It is shown here that by deploying a low-temperature AlO x (LT AlO x ) process, involving atomic layer deposition (ALD) of Al 2 O 3 at 50 °C with a chemical vapor deposition (CVD) component, a high nucleation density layer can be formed, which templates the growth of a high- k dielectric, such as HfO 2 . Atomic force microscopy (AFM) imaging shows that at 50 °C, the Al 2 O 3 spontaneously forms a pinhole-free, sub-2 nm layer on graphene. Density functional theory (DFT) based simulations indicate that the spreading out of AlO x clusters on the carbon surface enables conformal oxide deposition. Device applications of the LT AlO x deposition scheme were investigated through electrical measurements on metal oxide semiconductor capacitors (MOSCAPs) with Al 2 O 3 /HfO 2 bilayer gate oxides using both standard Ti/Pt metal gates as well as TiN/Ti/Pd gettering gates. In this study, LT AlO x was used to nucleate HfO 2 and it was shown that bilayer gate oxide stacks of 2.85 and 3.15 nm were able to achieve continuous coverage on carbon nanotubes (CNTs). The robustness of the bilayer was tested through deployment in a CNT-based field-effect transistor (FET) configuration with a gate leakage of less than 10 -8 A/μm per CNT.
Databáze:	MEDLINE
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