In this study, we investigated the applicability of an amorphous, high-permittivity (k) dielectric film La1-xTaxO y as an alternative gate insulator in next-generation complementary metal-oxide-semiconductor devices and metal-insulator-metal capacitors. La 1-xTaxOy films not only show a crystallization temperature higher than 1000 °C, but also a permittivity as high as 30. La1-xTaxOy films also have a much larger band gap than Ta2O5 films because of the coupling effect between the 5d orbitals of La and Ta atoms bonding to a common oxygen atom. Therefore, La1-xTaxOy films with appropriate Ta concentration are promising amorphous high- k gate insulators.
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