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Title: Initial reaction of hafnium oxide deposited by remote plasma atomic layer deposition method

Abstract

A remote plasma atomic layer deposition (RPALD) method has been applied to grow a hafnium oxide thin film on the Si substrate. The deposition process was monitored by in situ XPS and the as-deposited structure and chemical bonding were examined by TEM and XPS. The in situ XPS measurement showed the presence of a hafnium silicate phase at the initial stage of the RPALD process up to the 20th cycle and indicated that no hafnium silicide was formed. The initial hafnium silicate was amorphous and grew to a thickness of approximately 2 nm. Based on these results and model reactions for silicate formation, we proposed an initial growth mechanism that includes adatom migration at nascent step edges. Density functional theory calculations on model compounds indicate that the hafnium silicate is thermodynamically favored over the hafnium silicide by as much as 250 kJ/mol.

Authors:
; ; ; ; ;  [1];  [2]
  1. Department of Chemistry, Hanyang University, Seoul 133-791 (Korea, Republic of)
  2. (Korea, Republic of)
Publication Date:
OSTI Identifier:
20776928
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 87; Journal Issue: 26; Other Information: DOI: 10.1063/1.2150250; (c) 2005 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; CHEMICAL BONDS; CRYSTAL GROWTH; DENSITY FUNCTIONAL METHOD; DEPOSITION; HAFNIUM OXIDES; HAFNIUM SILICATES; HAFNIUM SILICIDES; LAYERS; PLASMA; SUBSTRATES; THICKNESS; THIN FILMS; TRANSMISSION ELECTRON MICROSCOPY; X-RAY PHOTOELECTRON SPECTROSCOPY

Citation Formats

Won, Youngdo, Park, Sangwook, Koo, Jaehyoung, Kim, Seokhoon, Kim, Jinwoo, Jeon, Hyeongtag, and Division of Materials Science and Engineering, Hanyang University, Seoul 133-791. Initial reaction of hafnium oxide deposited by remote plasma atomic layer deposition method. United States: N. p., 2005. Web. doi:10.1063/1.2150250.
Won, Youngdo, Park, Sangwook, Koo, Jaehyoung, Kim, Seokhoon, Kim, Jinwoo, Jeon, Hyeongtag, & Division of Materials Science and Engineering, Hanyang University, Seoul 133-791. Initial reaction of hafnium oxide deposited by remote plasma atomic layer deposition method. United States. doi:10.1063/1.2150250.
Won, Youngdo, Park, Sangwook, Koo, Jaehyoung, Kim, Seokhoon, Kim, Jinwoo, Jeon, Hyeongtag, and Division of Materials Science and Engineering, Hanyang University, Seoul 133-791. Mon . "Initial reaction of hafnium oxide deposited by remote plasma atomic layer deposition method". United States. doi:10.1063/1.2150250.
@article{osti_20776928,
title = {Initial reaction of hafnium oxide deposited by remote plasma atomic layer deposition method},
author = {Won, Youngdo and Park, Sangwook and Koo, Jaehyoung and Kim, Seokhoon and Kim, Jinwoo and Jeon, Hyeongtag and Division of Materials Science and Engineering, Hanyang University, Seoul 133-791},
abstractNote = {A remote plasma atomic layer deposition (RPALD) method has been applied to grow a hafnium oxide thin film on the Si substrate. The deposition process was monitored by in situ XPS and the as-deposited structure and chemical bonding were examined by TEM and XPS. The in situ XPS measurement showed the presence of a hafnium silicate phase at the initial stage of the RPALD process up to the 20th cycle and indicated that no hafnium silicide was formed. The initial hafnium silicate was amorphous and grew to a thickness of approximately 2 nm. Based on these results and model reactions for silicate formation, we proposed an initial growth mechanism that includes adatom migration at nascent step edges. Density functional theory calculations on model compounds indicate that the hafnium silicate is thermodynamically favored over the hafnium silicide by as much as 250 kJ/mol.},
doi = {10.1063/1.2150250},
journal = {Applied Physics Letters},
number = 26,
volume = 87,
place = {United States},
year = {Mon Dec 26 00:00:00 EST 2005},
month = {Mon Dec 26 00:00:00 EST 2005}
}
  • The plasma enhanced atomic layer deposition process for the HfO{sub 2} thin film is modeled as simple reactions between Hf(OH){sub 3}NH{sub 2} and reactive oxygen species. The density functional theory calculation was performed for plausible reaction pathways to construct the reaction profile. While the triplet molecular oxygen is unlikely to form a reactive complex, the singlet molecular oxygen forms the stable adduct that goes through the transition state and completes the reaction pathway to the products. Either two singlet or two triplet oxygen atoms make the singlet adduct complex, which follows the same pathway to the product as the singletmore » molecular oxygen reacts.« less
  • Al{sub 2}O{sub 3} films deposited by remote plasma atomic layer deposition have been used for thin film encapsulation of organic light emitting diode. In this study, a multi-density layer structure consisting of two Al{sub 2}O{sub 3} layers with different densities are deposited with different deposition conditions of O{sub 2} plasma reactant time. This structure improves moisture permeation barrier characteristics, as confirmed by a water vapor transmission rate (WVTR) test. The lowest WVTR of the multi-density layer structure was 4.7 × 10{sup −5} gm{sup −2} day{sup −1}, which is one order of magnitude less than WVTR for the reference single-density Al{submore » 2}O{sub 3} layer. This improvement is attributed to the location mismatch of paths for atmospheric gases, such as O{sub 2} and H{sub 2}O, in the film due to different densities in the layers. This mechanism is analyzed by high resolution transmission electron microscopy, elastic recoil detection, and angle resolved X-ray photoelectron spectroscopy. These results confirmed that the multi-density layer structure exhibits very good characteristics as an encapsulation layer via location mismatch of paths for H{sub 2}O and O{sub 2} between the two layers.« less
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