Materials 2012, 5(3), 512-527; doi:10.3390/ma5030512
Review

Study of Direct-Contact HfO2/Si Interfaces

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Received: 27 February 2012; in revised form: 5 March 2012 / Accepted: 8 March 2012 / Published: 19 March 2012
(This article belongs to the Special Issue High-k Materials and Devices)
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract: Controlling monolayer Si oxide at the HfO2/Si interface is a challenging issue in scaling the equivalent oxide thickness of HfO2/Si gate stack structures. A concept that the author proposes to control the Si oxide interface by using ultra-high vacuum electron-beam HfO2 deposition is described in this review paper, which enables the so-called direct-contact HfO2/Si structures to be prepared. The electrical characteristics of the HfO2/Si metal-oxide-semiconductor capacitors are reviewed, which suggest a sufficiently low interface state density for the operation of metal-oxide-semiconductor field-effect-transistors (MOSFETs) but reveal the formation of an unexpected strong interface dipole. Kelvin probe measurements of the HfO2/Si structures provide obvious evidence for the formation of dipoles at the HfO2/Si interfaces. The author proposes that one-monolayer Si-O bonds at the HfO2/Si interface naturally lead to a large potential difference, mainly due to the large dielectric constant of the HfO2. Dipole scattering is demonstrated to not be a major concern in the channel mobility of MOSFETs.
Keywords: MOSFET; high-k; HfO2; interface dipole; channel mobility
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MDPI and ACS Style

Miyata, N. Study of Direct-Contact HfO2/Si Interfaces. Materials 2012, 5, 512-527.

AMA Style

Miyata N. Study of Direct-Contact HfO2/Si Interfaces. Materials. 2012; 5(3):512-527.

Chicago/Turabian Style

Miyata, Noriyuki. 2012. "Study of Direct-Contact HfO2/Si Interfaces." Materials 5, no. 3: 512-527.


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