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Selected Works of Santosh KC
Article
Materials Design on the Origin of Gap States in a High-κ/GaAs Interface
Engineering (2016)
  • Weichao Wang, Nankai University
  • Cheng Gong, University of Texas at Dallas
  • Ka Xiong, University of Texas at Dallas
  • Santosh KC, University of Texas at Dallas
  • Robert M. Wallace, University of Texas at Dallas
  • Kyeongjae Cho, The University of Texas at Dallas
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Abstract
Given the demand for constantly scaling microelectronic devices to ever smaller dimensions, a SiO2 gate dielectric was substituted with a higher dielectric-constant material, Hf(Zr)O2, in order to minimize current leakage through dielectric thin film. However, upon interfacing with high dielectric constant (high-κ) dielectrics, the electron mobility in the conventional Si channel degrades due to Coulomb scattering, surface-roughness scattering, remote-phonon scattering, and dielectric-charge trapping. III-V and Ge are two promising candidates with superior mobility over Si. Nevertheless, Hf(Zr)O2/III-V(Ge) has much more complicated interface bonding than Si-based interfaces. Successful fabrication of a high-quality device critically depends on understanding and engineering the bonding configurations at Hf(Zr)O2/III-V(Ge) interfaces for the optimal design of device interfaces. Thus, an accurate atomic insight into the interface bonding and mechanism of interface gap states formation becomes essential. Here, we utilize first-principle calculations to investigate the interface between HfO2 and GaAs. Our study shows that As−As dimer bonding, Ga partial oxidation (between 3+ and 1+) and Ga− dangling bonds constitute the major contributions to gap states. These findings provide insightful guidance for optimum interface passivation.
Keywords
  • high-mobility device,
  • high-κ/III-V interface,
  • interfacial gap states,
  • first-principle calculations
Disciplines
Publication Date
March 16, 2016
DOI
10.15302/J-ENG-2015052
Publisher Statement
SJSU users: Use the following link to login and access the article via SJSU databases.
This article was published in Engineering, volume 1, issue 3, 2016, and can also be found online here.
Citation Information
Weichao Wang, Cheng Gong, Ka Xiong, Santosh KC, et al.. "Materials Design on the Origin of Gap States in a High-κ/GaAs Interface" Engineering Vol. 1 Iss. 3 (2016) p. 372 - 377 ISSN: 2095-8099
Available at: http://works.bepress.com/santosh-kc/17/