• Otomo, Masaki
• Ono, Ryo

Abstract

<jats:title>Abstract</jats:title><jats:p>Zirconium disulfide (ZrS<jats:sub>2</jats:sub>)—an attractive next-generation channel material because of its high mobility—is stabilized in the air by a zirconium dioxide (ZrO<jats:sub>2</jats:sub>) film which functions as a high-k film in MISFET. We fabricated high-k/PVD-ZrS<jats:sub>2</jats:sub> stacks with a self-oxidized ZrO<jats:sub>2</jats:sub> film as an interfacial layer; their chemical properties were analyzed to clarify how each fabrication process affects the ZrS<jats:sub>2</jats:sub> under the oxide film. The results clarified that sulfur vapor annealing (SVA) is critical for fabricating high-quality physical vapor deposition (PVD) ZrS<jats:sub>2</jats:sub> films and that the change in surface potential of the ZrS<jats:sub>2</jats:sub> films due to interface dipoles between the high-k and Zr-compound films is suppressed with scaling of high-k thickness. The SVA with high-k films also prevents degradation of crystallinity and stoichiometry, enhancing the quality of the ZrS<jats:sub>2</jats:sub> films without affecting their surface potential. These achievements enable us to control the threshold voltage in ZrS<jats:sub>2</jats:sub> MISFETs.</jats:p>

Topics

• impedance spectroscopy
• surface
• compound
• mobility
• zirconium
• physical vapor deposition
• annealing
• crystallinity
• zirconium dioxide