Significant Enhancement of the Dielectric Constant through the Doping of CeO2 into HfO2 by Atomic Layer Deposition. Issue 4 (6th January 2014)

• Record Type: Journal Article
• Authors: Kim, Woo‐Hee; Kim, Min‐Kyu; Oh, Il‐Kwon; Maeng, Wan Joo; Cheon, Taehoon; Kim, Soo‐Hyun; Noori, Atif; Thompson, David; Chu, Schubert; Kim, Hyungjun; Dunn, B.
• Is Part Of: Journal of the American Ceramic Society. Volume 97:Issue 4(2014)
• Page Start: 1164
• Page End: 1169
• Publication Date: 2014-01-06
• Subjects: Ceramics -- Periodicals; 620.1405
• DOI: 10.1111/jace.12762
• Languages: English
• ISSNs: 0002-7820

Abstract

<abstract abstract-type="main" id="jace12762-abs-0001"> <title> <x xml:space="preserve">Abstract</x> </title> <p>Films of CeO<sub>2</sub> were deposited by atomic layer deposition (ALD) using a Ce(mmp)<sub>4</sub> [mmp = 1‐methoxy‐2‐methyl‐2‐propanolate] precursor and H<sub>2</sub>O reactant. The growth characteristics and film properties of ALD CeO<sub>2</sub> were investigated. The ALD CeO<sub>2</sub> process produced highly pure, stoichiometric films with polycrystalline cubic phases. Using the ALD CeO<sub>2</sub> process, the effects of Ce doping into an HfO<sub>2</sub> gate dielectric were systematically investigated. Regardless of Ce/(Ce + Hf) composition, all ALD Ce<sub><italic>x</italic></sub>Hf<sub>1−<italic>x</italic></sub>O<sub>2</sub> films exhibited constant growth rates of approximately 1.3 Å/cycle, which is essentially identical to the ALD HfO<sub>2</sub> growth rates. After high‐temperature vacuum annealing at 900°C, it was verified, based on X‐ray diffraction and high‐resolution cross‐sectional transmission electron microscopy results, that all samples with various Ce/(Ce + Hf) compositions were transformed from nanocrystalline to stabilized cubic or tetragonal HfO<sub>2</sub> phases. In addition, the dielectric constant of the Ce<sub><italic>x</italic></sub>Hf<sub>1−<italic>x</italic></sub>O<sub>2</sub> films significantly increased, depending on the Ce doping content. The maximum dielectric constant value was found to be nearly 39 for the Ce/(Ce + Hf) concentration of ~11%.</p> </abstract>