skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Evaluation of Alternative Atomistic Models for the Incipient Growth of ZnO by Atomic Layer Deposition

Abstract

ZnO thin films are interesting for applications in several technological fields, including optoelectronics and renewable energies. Nanodevice applications require controlled synthesis of ZnO structures at nanometer scale, which can be achieved via atomic layer deposition (ALD). However, the mechanisms governing the initial stages of ALD had not been addressed until very recently. Investigations into the initial nucleation and growth as well as the atomic structure of the heterointerface are crucial to optimize the ALD process and understand the structure-property relationships for ZnO. We have used a complementary suite of in situ synchrotron x-ray techniques to investigate both the structural and chemical evolution during ZnO growth by ALD on two different substrates, i.e., SiO2 and Al2O3, which led us to formulate an atomistic model of the incipient growth of ZnO. The model relies on the formation of nanoscale islands of different size and aspect ratio and consequent disorder induced in the Zn neighbors' distribution. However, endorsement of our model requires testing and discussion of possible alternative models which could account for the experimental results. In this work, we review, test, and rule out several alternative models; the results confirm our view of the atomistic mechanisms at play, which influence the overallmore » microstructure and resulting properties of the final thin film.« less

Authors:
; ; ; ; ; ; ; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org.:
Agence Nationale de la recherche (ANR); Hanoi University of Science and Technology; USDOE Office of Science - Office of Basic Energy Sciences - Materials Sciences and Engineering Division; Synchrotron SOLEIL
OSTI Identifier:
1366713
DOE Contract Number:
AC02-06CH11357
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Electronic Materials; Journal Volume: 46; Journal Issue: 6
Country of Publication:
United States
Language:
English
Subject:
ALD; XANES; ZnO; in situ; simulations; synchrotron radiation

Citation Formats

Chu, Manh-Hung, Tian, Liang, Chaker, Ahmad, Skopin, Evgenii, Cantelli, Valentina, Ouled, Toufik, Boichot, Raphaël, Crisci, Alexandre, Lay, Sabine, Richard, Marie-Ingrid, Thomas, Olivier, Deschanvres, Jean-Luc, Renevier, Hubert, Fong, Dillon, and Ciatto, Gianluca. Evaluation of Alternative Atomistic Models for the Incipient Growth of ZnO by Atomic Layer Deposition. United States: N. p., 2017. Web. doi:10.1007/s11664-017-5448-2.
Chu, Manh-Hung, Tian, Liang, Chaker, Ahmad, Skopin, Evgenii, Cantelli, Valentina, Ouled, Toufik, Boichot, Raphaël, Crisci, Alexandre, Lay, Sabine, Richard, Marie-Ingrid, Thomas, Olivier, Deschanvres, Jean-Luc, Renevier, Hubert, Fong, Dillon, & Ciatto, Gianluca. Evaluation of Alternative Atomistic Models for the Incipient Growth of ZnO by Atomic Layer Deposition. United States. doi:10.1007/s11664-017-5448-2.
Chu, Manh-Hung, Tian, Liang, Chaker, Ahmad, Skopin, Evgenii, Cantelli, Valentina, Ouled, Toufik, Boichot, Raphaël, Crisci, Alexandre, Lay, Sabine, Richard, Marie-Ingrid, Thomas, Olivier, Deschanvres, Jean-Luc, Renevier, Hubert, Fong, Dillon, and Ciatto, Gianluca. Mon . "Evaluation of Alternative Atomistic Models for the Incipient Growth of ZnO by Atomic Layer Deposition". United States. doi:10.1007/s11664-017-5448-2.
@article{osti_1366713,
title = {Evaluation of Alternative Atomistic Models for the Incipient Growth of ZnO by Atomic Layer Deposition},
author = {Chu, Manh-Hung and Tian, Liang and Chaker, Ahmad and Skopin, Evgenii and Cantelli, Valentina and Ouled, Toufik and Boichot, Raphaël and Crisci, Alexandre and Lay, Sabine and Richard, Marie-Ingrid and Thomas, Olivier and Deschanvres, Jean-Luc and Renevier, Hubert and Fong, Dillon and Ciatto, Gianluca},
abstractNote = {ZnO thin films are interesting for applications in several technological fields, including optoelectronics and renewable energies. Nanodevice applications require controlled synthesis of ZnO structures at nanometer scale, which can be achieved via atomic layer deposition (ALD). However, the mechanisms governing the initial stages of ALD had not been addressed until very recently. Investigations into the initial nucleation and growth as well as the atomic structure of the heterointerface are crucial to optimize the ALD process and understand the structure-property relationships for ZnO. We have used a complementary suite of in situ synchrotron x-ray techniques to investigate both the structural and chemical evolution during ZnO growth by ALD on two different substrates, i.e., SiO2 and Al2O3, which led us to formulate an atomistic model of the incipient growth of ZnO. The model relies on the formation of nanoscale islands of different size and aspect ratio and consequent disorder induced in the Zn neighbors' distribution. However, endorsement of our model requires testing and discussion of possible alternative models which could account for the experimental results. In this work, we review, test, and rule out several alternative models; the results confirm our view of the atomistic mechanisms at play, which influence the overall microstructure and resulting properties of the final thin film.},
doi = {10.1007/s11664-017-5448-2},
journal = {Journal of Electronic Materials},
number = 6,
volume = 46,
place = {United States},
year = {Mon Mar 20 00:00:00 EDT 2017},
month = {Mon Mar 20 00:00:00 EDT 2017}
}
  • The ability to synthesize semiconductor nanowires with deterministic and tunable control of orientation and morphology on a wide range of substrates, while high precision and repeatability are maintained, is a challenge currently faced for the development of many nanoscale material systems. Here we show that atomic layer deposition (ALD) presents a reliable method of surface and interfacial modification to guide nanowire orientation on a variety of substrate materials and geometries, including high-aspect-ratio, three-dimensional templates. We demonstrate control of the orientation and geometric properties of hydrothermally grown single crystalline ZnO nanowires via the deposition of a ZnO seed layer by ALD.more » The crystallographic texture and roughness of the seed layer result in tunable preferred nanowire orientations and densities for identical hydrothermal growth conditions. The structural and chemical relationship between the ALD layers and nanowires was investigated with synchrotron X-ray diffraction, high-resolution transmission electron microscopy, and X-ray photoelectron spectroscopy to elucidate the underlying mechanisms of orientation and morphology control. The resulting control parameters were utilized to produce hierarchical nanostructures with tunable properties on a wide range of substrates, including vertical micropillars, paper fibers, porous polymer membranes, and biological substrates. This illustrates the power of ALD for interfacial engineering of heterogeneous material systems at the nanoscale, to provide a highly controlled and scalable seeding method for bottom-up synthesis of integrated nanosystems.« less
  • We report on the zinc oxide (ZnO) thin films obtained by the atomic layer deposition (ALD) method using diethyl zinc and water precursors, which allowed us to lower deposition temperature to below 200 deg. C. The so-obtained 'as grown' ZnO layers are polycrystalline and show excitonic photoluminescence (PL) at room temperature, even if the deposition temperature was lowered down to 100 deg. C. Defect-related PL bands are of low intensity and are absent for layers grown at 140-200 deg. C. This is evidence that extremely low temperature growth by ALD can result in high quality ZnO thin films with inefficientmore » nonradiative decay channels and with thermodynamically blocked self-compensation processes.« less
  • An inductively coupled plasma technique (ICP), namely, remote-plasma treatment was introduced to ionize the water molecules as the precursor for the deposition of ZnO film via the atomic layer deposition processes. Compared with the H{sub 2}O gas as the precursor for the ALD growth, the ionized water molecules can provide a lesser energy to uniformly stabilize oxidization processes, resulting in a better film quality with a higher resistivity owing to less formation of intrinsic defects at a lower growth temperature. The relationship between resistivity and formation mechanisms have been discussed and investigated through analyses of atomic force microscopy, photonluminescence, andmore » absorption spectra, respectively. Findings indicate that the steric hindrance of the ligands plays an important rule for the ALD-ZnO film sample with the ICP treatment while the limited number of bonding sites will be dominant for the ALD-ZnO film without the ICP treatment owing to decreasing of the reactive sites via the ligand-exchange reaction during the dissociation process. Finally, the enhanced aspect-ratio into the anodic aluminum oxide with the better improved uniform coating of ZnO layer after the ICP treatment was demonstrated, providing an important information for a promising application in electronics based on ZnO ALD films.« less
  • ZnO films were grown by atomic layer deposition at 35 °C on poly(methyl methacrylate) substrates using diethylzinc and water precursors. The film growth, morphology, and crystallinity were studied using Rutherford backscattering spectrometry, time-of-flight elastic recoil detection analysis, atomic force microscopy, scanning electron microscopy, and x-ray diffraction. The uniform film growth was reached after several hundreds of deposition cycles, preceded by the precursor penetration into the porous bulk and island-type growth. After the full surface coverage, the ZnO films were stoichiometric, and consisted of large grains (diameter 30 nm) with a film surface roughness up to 6 nm (RMS). The introduction of Al{sub 2}O{submore » 3} seed layer enhanced the initial ZnO growth substantially and changed the surface morphology as well as the crystallinity of the deposited ZnO films. Furthermore, the water contact angles of the ZnO films were measured, and upon ultraviolet illumination, the ZnO films on all the substrates became hydrophilic, independent of the film crystallinity.« less