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Title: Effect of growth rate on crystallization of HfO{sub 2} thin films deposited by RF magnetron sputtering

Abstract

Hafnium oxide (HfO{sub 2}) is the potentially useful dielectric material in both; electronics to replace the conventional SiO{sub 2} as gate dielectric and in Optics as anti-reflection coating material. In this present work we have synthesized polycrystalline HfO{sub 2} thin films by RF magnetron sputtering deposition technique with varying target to substrate distance. The deposited films were characterized by X-ray Diffraction, Rutherford Backscattering Spectrometry (RBS) and transmission and Reflection (T&R) measurements to study the growth behavior, microstructure and optical properties. XRD measurement shows that the samples having mixed phase of monoclinic, cubic and tetragonal crystal structure. RBS measurements suggest the formation of Inter Layer (IL) in between Substrate and film.

Authors:
; ; ;  [1]
  1. School of Physics, University of Hyderabad, Hyderabad, India 500046 (India)
Publication Date:
OSTI Identifier:
22608720
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1731; Journal Issue: 1; Conference: DAE solid state physics symposium 2015, Uttar Pradesh (India), 21-25 Dec 2015; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; CRYSTALLIZATION; DEPOSITION; DIELECTRIC MATERIALS; HAFNIUM OXIDES; LAYERS; MAGNETRONS; MICROSTRUCTURE; MONOCLINIC LATTICES; OPTICAL PROPERTIES; POLYCRYSTALS; REFLECTION; RUTHERFORD BACKSCATTERING SPECTROSCOPY; SILICON OXIDES; SPUTTERING; SUBSTRATES; THIN FILMS; TRANSMISSION; X-RAY DIFFRACTION

Citation Formats

Dhanunjaya, M., Manikanthababu, N., Pathak, A. P., and Rao, S. V. S. Nageswara, E-mail: svnsp@uohyd.ernet.in. Effect of growth rate on crystallization of HfO{sub 2} thin films deposited by RF magnetron sputtering. United States: N. p., 2016. Web. doi:10.1063/1.4947949.
Dhanunjaya, M., Manikanthababu, N., Pathak, A. P., & Rao, S. V. S. Nageswara, E-mail: svnsp@uohyd.ernet.in. Effect of growth rate on crystallization of HfO{sub 2} thin films deposited by RF magnetron sputtering. United States. doi:10.1063/1.4947949.
Dhanunjaya, M., Manikanthababu, N., Pathak, A. P., and Rao, S. V. S. Nageswara, E-mail: svnsp@uohyd.ernet.in. 2016. "Effect of growth rate on crystallization of HfO{sub 2} thin films deposited by RF magnetron sputtering". United States. doi:10.1063/1.4947949.
@article{osti_22608720,
title = {Effect of growth rate on crystallization of HfO{sub 2} thin films deposited by RF magnetron sputtering},
author = {Dhanunjaya, M. and Manikanthababu, N. and Pathak, A. P. and Rao, S. V. S. Nageswara, E-mail: svnsp@uohyd.ernet.in},
abstractNote = {Hafnium oxide (HfO{sub 2}) is the potentially useful dielectric material in both; electronics to replace the conventional SiO{sub 2} as gate dielectric and in Optics as anti-reflection coating material. In this present work we have synthesized polycrystalline HfO{sub 2} thin films by RF magnetron sputtering deposition technique with varying target to substrate distance. The deposited films were characterized by X-ray Diffraction, Rutherford Backscattering Spectrometry (RBS) and transmission and Reflection (T&R) measurements to study the growth behavior, microstructure and optical properties. XRD measurement shows that the samples having mixed phase of monoclinic, cubic and tetragonal crystal structure. RBS measurements suggest the formation of Inter Layer (IL) in between Substrate and film.},
doi = {10.1063/1.4947949},
journal = {AIP Conference Proceedings},
number = 1,
volume = 1731,
place = {United States},
year = 2016,
month = 5
}
  • The crystallization properties of amorphous silicon (a-Si) thin film deposited by rf magnetron sputter deposition with substrate bias have been thoroughly characterized. The crystallization kinetics for films deposited with substrate bias is enhanced relative to unbiased a-Si by films. The enhanced crystallization for substrate biased a-Si films are attributed to ion enhanced nucleation of crystallites during sputter deposition which subsequently grow during the postdeposition anneal. Conversely films sputter deposited without substrate bias have more intrinsic defects and residual oxygen which enhance nucleation and retard growth, respectively, and lead to a large number of small crystallites.
  • Ruthenium is deposited by DC magnetron sputtering at different powers and is characterized. The effect of sputtering power on the electrical and structural properties of the film is investigated experimentally. High resolution X-ray diffraction is used to characterize the microstructure of Ru films deposited on SiO{sub 2} surface. The peak (002) is more sharp and intense with full width at half maximum (FWHM) of 0.37° at 250W. The grain size increases with increase in sputtering power improving the crystallinity of the film. The film deposited at high sputtering power also showed lower resistivity (12.40 µΩ-cm) and higher mobility (4.82 cm{sup 2}/V.s) asmore » compared to the film deposited at low power. The surface morphology of the film is studied by atomic force microscopy (AFM).« less
  • Epitaxial domain formation and textured growth in AlN thin films deposited on Si(001) substrates by reactive magnetron sputtering was studied by transmission electron microscopy and x-ray diffraction. The films have a wurtzite type structure with a crystallographic orientation relationship to the silicon substrate of AlN(0001)(parallel sign)Si(001). The AlN film is observed to nucleate randomly on the Si surface and grows three dimensionally, forming columnar domains. The in-plane orientation reveals four domains with their a axes rotated by 15 deg. with respect to each other: AlN<1120>(parallel sign)Si[110], AlN<0110>(parallel sign)Si[110], AlN<1120>(parallel sign)Si[100], and AlN<0110>(parallel sign)Si[100] An explanation of the growth mode basedmore » on the large lattice mismatch and the topology of the substrate surface is proposed.« less
  • The nucleation and growth of Ti{sub 2}AlN thin films on MgO(111) substrates during dual direct current reactive magnetron cosputtering from Ti and Al targets in an Ar/N{sub 2} atmosphere at a substrate temperature of 690 deg. C have been investigated. Time and thickness dependent in situ specular x-ray reflectivity and x-ray diffraction in combination with cross-sectional transmission electron microscopy and Rutherford backscattering spectroscopy reveal the formation of competing phases for slight N superstoichiometry with respect to Ti{sub 2}AlN. The stoichiometry deviations initiate the layer-by-layer growth of a {approx}380 A ring thick epitaxial N-substoichiometric cubic (Ti{sub 1-x}Al{sub x})N{sub y} layer. N-vacancymore » driven diffusion of Ti and Al leads to decomposition of this metastable solid solution into nanosized cubic TiN{sub y{sup '}} and AlN{sub y{sup ''}} domains as well as to a solid-state reaction with the MgO(111) by formation of a Mg{sub 2}(Al:Ti)O{sub 4} spinel, reducing the transformed (Ti{sub 1-x}Al{sub x})N{sub y} layer thickness down to {approx}60 A ring . Local AlN{sub y{sup ''}} domains serve as templates for Ti{sub 2}AlN nucleation at higher thicknesses. At the same time TiN{sub y{sup '}} and AlN{sub y{sup ''}} serve as a sink for excess gas phase N during the subsequent polycrystalline Ti{sub 2}AlN growth with random (Ti{sub 1-x}Al{sub x})N{sub y} renucleation as a tissue phase along Ti{sub 2}AlN grain boundaries. The individual Ti{sub 2}AlN grains with vertical sizes up to the total thickness retain local epitaxy to the substrate, with basal planes nonparallel to the substrate interface. Concurrently the (Ti{sub 1-x}Al{sub x})N{sub y} layer is further reduced by inward Ti{sub 2}AlN grain growth along the basal planes.« less
  • We have recently shown that AlN (0002) (c axis) is tilted abruptly toward the deposition direction as N{sub 2} concentration is increased in N{sub 2}/Ar sputtering gas mixtures. Here, we present a Monte Carlo simulation model to describe the phenomenon of sudden c-axis AlN tilt. The model is based on the assumption that AlN islands with their c axis parallel to substrate normal and AlN islands with tilted c axis coexist at the initial stages of the growth and they can provide the adatoms with different surface mobilities. It is believed that the adatom mobilities are quenched when N{sub 2}more » concentration reaches a certain amount in the reactive sputtering of AlN. Our model further assumes that adatom mobility differences on different islands result in a growth rate difference of the islands. At the initial stages of the growth, AlN islands with tilted c axis grow taller due to the lower adatom mobility on these islands. As they grow taller, they win the competition and stop the further growth of AlN islands with their c axis parallel to substrate normal due to shadowing effect. Monte Carlo simulations revealed that the shadowing effect combined with different adatom mobilities promotes the sudden c-axis tilt in AlN thin films.« less