Structural and optical properties of post-annealed atomic-layer-deposited HfO2 thin films on GaAs

N. S. Bennett; K. Cherkaoui; C. S. Wong; E. O'Connor; S. Monaghan; P. Hurley; L. Chauhan; P. J. McNally

doi:10.1016/j.tsf.2014.08.025

Structural and optical properties of post-annealed atomic-layer-deposited HfO2 thin films on GaAs

N. S. Bennett^*, K. Cherkaoui, C. S. Wong, E. O'Connor, S. Monaghan, P. Hurley, L. Chauhan, P. J. McNally

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

3 Citations (Scopus)

Abstract

The effects of post-annealing conditions on solid-phase crystallization of atomic-layer-deposited HfO2 films grown on GaAs were investigated. Film properties, including crystallinity (preferential crystal orientation and crystallite size), thickness, density, permittivity, optical band gap and chemical composition were monitored as a function of annealing conditions. Following rapid thermal processing (RTP) in nitrogen ambient at temperatures from 325 degrees C to 625 degrees C, the initially produced amorphous/partially crystallized HfO2 films changed into a well-ordered crystalline structure with no detectable interfacial layer between the film and the GaAs substrate. Though HfO2 properties were predictable and similar to those of HfO2 on Si for low temperature processing, in the case of annealing at >= 475 degrees C, the thickness of the film was relatively increased compared to that of an as-grown film and displayed unexpected film characteristics. Changes after annealing in the depth profile data related to stoichiometry indicated that As oxide is formed within the HfO2 film during the RTP. The formation of As oxide in the HfO2 film, resulting from the underlying substrate, is dissimilar to previously published results which reported the presence of Ga oxide. (C) 2014 Elsevier B.V. All rights reserved.

Original language	English
Pages (from-to)	104-112
Number of pages	9
Journal	Thin Solid Films
Volume	569
DOIs	https://doi.org/10.1016/j.tsf.2014.08.025
Publication status	Published - 31 Oct 2014

Keywords

Hafnia
Gallium arsenide
Atomic layer deposition
Dielectric properties
High dielectric constant materials
DIELECTRIC-CONSTANT
GATE DIELECTRICS
CRYSTALLIZATION
OXIDES

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10.1016/j.tsf.2014.08.025

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title = "Structural and optical properties of post-annealed atomic-layer-deposited HfO2 thin films on GaAs",

abstract = "The effects of post-annealing conditions on solid-phase crystallization of atomic-layer-deposited HfO2 films grown on GaAs were investigated. Film properties, including crystallinity (preferential crystal orientation and crystallite size), thickness, density, permittivity, optical band gap and chemical composition were monitored as a function of annealing conditions. Following rapid thermal processing (RTP) in nitrogen ambient at temperatures from 325 degrees C to 625 degrees C, the initially produced amorphous/partially crystallized HfO2 films changed into a well-ordered crystalline structure with no detectable interfacial layer between the film and the GaAs substrate. Though HfO2 properties were predictable and similar to those of HfO2 on Si for low temperature processing, in the case of annealing at >= 475 degrees C, the thickness of the film was relatively increased compared to that of an as-grown film and displayed unexpected film characteristics. Changes after annealing in the depth profile data related to stoichiometry indicated that As oxide is formed within the HfO2 film during the RTP. The formation of As oxide in the HfO2 film, resulting from the underlying substrate, is dissimilar to previously published results which reported the presence of Ga oxide. (C) 2014 Elsevier B.V. All rights reserved.",

keywords = "Hafnia, Gallium arsenide, Atomic layer deposition, Dielectric properties, High dielectric constant materials, DIELECTRIC-CONSTANT, GATE DIELECTRICS, CRYSTALLIZATION, OXIDES",

author = "Bennett, {N. S.} and K. Cherkaoui and Wong, {C. S.} and E. O'Connor and S. Monaghan and P. Hurley and L. Chauhan and McNally, {P. J.}",

year = "2014",

month = oct,

day = "31",

doi = "10.1016/j.tsf.2014.08.025",

language = "English",

volume = "569",

pages = "104--112",

journal = "Thin Solid Films",

issn = "0040-6090",

publisher = "Elsevier",

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T1 - Structural and optical properties of post-annealed atomic-layer-deposited HfO2 thin films on GaAs

AU - Bennett, N. S.

AU - Cherkaoui, K.

AU - Wong, C. S.

AU - O'Connor, E.

AU - Monaghan, S.

AU - Hurley, P.

AU - Chauhan, L.

AU - McNally, P. J.

PY - 2014/10/31

Y1 - 2014/10/31

N2 - The effects of post-annealing conditions on solid-phase crystallization of atomic-layer-deposited HfO2 films grown on GaAs were investigated. Film properties, including crystallinity (preferential crystal orientation and crystallite size), thickness, density, permittivity, optical band gap and chemical composition were monitored as a function of annealing conditions. Following rapid thermal processing (RTP) in nitrogen ambient at temperatures from 325 degrees C to 625 degrees C, the initially produced amorphous/partially crystallized HfO2 films changed into a well-ordered crystalline structure with no detectable interfacial layer between the film and the GaAs substrate. Though HfO2 properties were predictable and similar to those of HfO2 on Si for low temperature processing, in the case of annealing at >= 475 degrees C, the thickness of the film was relatively increased compared to that of an as-grown film and displayed unexpected film characteristics. Changes after annealing in the depth profile data related to stoichiometry indicated that As oxide is formed within the HfO2 film during the RTP. The formation of As oxide in the HfO2 film, resulting from the underlying substrate, is dissimilar to previously published results which reported the presence of Ga oxide. (C) 2014 Elsevier B.V. All rights reserved.

AB - The effects of post-annealing conditions on solid-phase crystallization of atomic-layer-deposited HfO2 films grown on GaAs were investigated. Film properties, including crystallinity (preferential crystal orientation and crystallite size), thickness, density, permittivity, optical band gap and chemical composition were monitored as a function of annealing conditions. Following rapid thermal processing (RTP) in nitrogen ambient at temperatures from 325 degrees C to 625 degrees C, the initially produced amorphous/partially crystallized HfO2 films changed into a well-ordered crystalline structure with no detectable interfacial layer between the film and the GaAs substrate. Though HfO2 properties were predictable and similar to those of HfO2 on Si for low temperature processing, in the case of annealing at >= 475 degrees C, the thickness of the film was relatively increased compared to that of an as-grown film and displayed unexpected film characteristics. Changes after annealing in the depth profile data related to stoichiometry indicated that As oxide is formed within the HfO2 film during the RTP. The formation of As oxide in the HfO2 film, resulting from the underlying substrate, is dissimilar to previously published results which reported the presence of Ga oxide. (C) 2014 Elsevier B.V. All rights reserved.

KW - Hafnia

KW - Gallium arsenide

KW - Atomic layer deposition

KW - Dielectric properties

KW - High dielectric constant materials

KW - DIELECTRIC-CONSTANT

KW - GATE DIELECTRICS

KW - CRYSTALLIZATION

KW - OXIDES

U2 - 10.1016/j.tsf.2014.08.025

DO - 10.1016/j.tsf.2014.08.025

M3 - Article

SN - 0040-6090

VL - 569

SP - 104

EP - 112

JO - Thin Solid Films

JF - Thin Solid Films

ER -

Structural and optical properties of post-annealed atomic-layer-deposited HfO2 thin films on GaAs

Abstract

Keywords

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