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Title: Growth dynamics of reactive-sputtering-deposited AlN films

Abstract

We have studied the surface kinetic roughening of AlN films grown on Si(100) substrates by dc reactive sputtering within the framework of the dynamic scaling theory. Films deposited under the same experimental conditions for different growth times were analyzed by atomic force microscopy and x-ray diffraction. The AlN films display a (002) preferred orientation. We have found two growth regimes with a crossover time of 36 min. In the first regime, the growth dynamics is unstable and the films present two types of textured domains, well textured and randomly oriented, respectively. In contrast, in the second regime the films are homogeneous and well textured, leading to a relative stabilization of the surface roughness characterized by a growth exponent {beta}=0.37{+-}0.03. In this regime a superrough scaling behavior is found with the following exponents: (i) Global exponents: roughness exponent {alpha}=1.2{+-}0.2 and {beta}=0.37{+-}0.03 and coarsening exponent 1/z=0.32{+-}0.05; (ii) local exponents: {alpha}{sub loc}=1, {beta}{sub loc}=0.32{+-}0.01. The differences between the growth modes are found to be related to the different main growth mechanisms dominating their growth dynamics: sticking anisotropy and shadowing, respectively.

Authors:
; ; ; ; ;  [1];  [2];  [3];  [3]
  1. Instituto de Ciencia de Materiales de Madrid-Consejo Superior de Investigaciones Cientificas CSIC, C-Sor Juana Ines de la Cruz 3, E-28049, Cantoblanco, Madrid (Spain)
  2. (Slovakia)
  3. (Spain)
Publication Date:
OSTI Identifier:
20711756
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 97; Journal Issue: 12; Other Information: DOI: 10.1063/1.1937467; (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; ALUMINIUM NITRIDES; ANISOTROPY; ATOMIC FORCE MICROSCOPY; CRYSTAL GROWTH; DEPOSITION; GRAIN ORIENTATION; ROUGHNESS; SEMICONDUCTOR MATERIALS; SPUTTERING; STABILIZATION; SUBSTRATES; SURFACES; THIN FILMS; X-RAY DIFFRACTION

Citation Formats

Auger, M.A., Vazquez, L., Sanchez, O., Jergel, M., Cuerno, R., Castro, M., Institute of Physics, Slovak Academy of Sciences, Dubravska cesta 9, 845 11 Bratislava 45, Departamento de Matematicas and Grupo Interdisciplinar de Sistemas Complejos, Universidad Carlos III de Madrid, Avenida de la Universidad 30, E-28911, Leganes, Madrid, and Grupo Interdisciplinar de Sistemas Complejos and Grupo de Dinamica No Lineal, Escuela Tecnica Superior de Ingenieria ICAI, Universidad Pontificia Comillas, E-28015, Madrid. Growth dynamics of reactive-sputtering-deposited AlN films. United States: N. p., 2005. Web. doi:10.1063/1.1937467.
Auger, M.A., Vazquez, L., Sanchez, O., Jergel, M., Cuerno, R., Castro, M., Institute of Physics, Slovak Academy of Sciences, Dubravska cesta 9, 845 11 Bratislava 45, Departamento de Matematicas and Grupo Interdisciplinar de Sistemas Complejos, Universidad Carlos III de Madrid, Avenida de la Universidad 30, E-28911, Leganes, Madrid, & Grupo Interdisciplinar de Sistemas Complejos and Grupo de Dinamica No Lineal, Escuela Tecnica Superior de Ingenieria ICAI, Universidad Pontificia Comillas, E-28015, Madrid. Growth dynamics of reactive-sputtering-deposited AlN films. United States. doi:10.1063/1.1937467.
Auger, M.A., Vazquez, L., Sanchez, O., Jergel, M., Cuerno, R., Castro, M., Institute of Physics, Slovak Academy of Sciences, Dubravska cesta 9, 845 11 Bratislava 45, Departamento de Matematicas and Grupo Interdisciplinar de Sistemas Complejos, Universidad Carlos III de Madrid, Avenida de la Universidad 30, E-28911, Leganes, Madrid, and Grupo Interdisciplinar de Sistemas Complejos and Grupo de Dinamica No Lineal, Escuela Tecnica Superior de Ingenieria ICAI, Universidad Pontificia Comillas, E-28015, Madrid. Wed . "Growth dynamics of reactive-sputtering-deposited AlN films". United States. doi:10.1063/1.1937467.
@article{osti_20711756,
title = {Growth dynamics of reactive-sputtering-deposited AlN films},
author = {Auger, M.A. and Vazquez, L. and Sanchez, O. and Jergel, M. and Cuerno, R. and Castro, M. and Institute of Physics, Slovak Academy of Sciences, Dubravska cesta 9, 845 11 Bratislava 45 and Departamento de Matematicas and Grupo Interdisciplinar de Sistemas Complejos, Universidad Carlos III de Madrid, Avenida de la Universidad 30, E-28911, Leganes, Madrid and Grupo Interdisciplinar de Sistemas Complejos and Grupo de Dinamica No Lineal, Escuela Tecnica Superior de Ingenieria ICAI, Universidad Pontificia Comillas, E-28015, Madrid},
abstractNote = {We have studied the surface kinetic roughening of AlN films grown on Si(100) substrates by dc reactive sputtering within the framework of the dynamic scaling theory. Films deposited under the same experimental conditions for different growth times were analyzed by atomic force microscopy and x-ray diffraction. The AlN films display a (002) preferred orientation. We have found two growth regimes with a crossover time of 36 min. In the first regime, the growth dynamics is unstable and the films present two types of textured domains, well textured and randomly oriented, respectively. In contrast, in the second regime the films are homogeneous and well textured, leading to a relative stabilization of the surface roughness characterized by a growth exponent {beta}=0.37{+-}0.03. In this regime a superrough scaling behavior is found with the following exponents: (i) Global exponents: roughness exponent {alpha}=1.2{+-}0.2 and {beta}=0.37{+-}0.03 and coarsening exponent 1/z=0.32{+-}0.05; (ii) local exponents: {alpha}{sub loc}=1, {beta}{sub loc}=0.32{+-}0.01. The differences between the growth modes are found to be related to the different main growth mechanisms dominating their growth dynamics: sticking anisotropy and shadowing, respectively.},
doi = {10.1063/1.1937467},
journal = {Journal of Applied Physics},
number = 12,
volume = 97,
place = {United States},
year = {Wed Jun 15 00:00:00 EDT 2005},
month = {Wed Jun 15 00:00:00 EDT 2005}
}
  • 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
  • The influence of the surface morphology of a molybdenum underlayer on the crystallinity and etchability of reactively sputtered c-axis oriented aluminum nitride thin films was investigated. Atomic force microscopy, scanning electron microscopy, transmission electron microscopy, high resolution x-ray diffraction, and defect selective chemical etching were used to characterize the microstructure of the Mo and AlN films. 1000 nm thick films of AlN with a full width at half maximum (FWHM) of the x-ray rocking curve ranging from 1.1 deg. to 1.9 deg. were deposited on 300 nm thick Mo underlayers with a FWHM of around 1.5 deg. The Ar pressuremore » during the Mo deposition had a critical effect on the Mo film surface morphology, affecting the structure of the subsequently deposited AlN films and, hence, their wet etching characteristics. AlN films deposited on Mo sputtered at a relatively high pressure could not be etched completely, while AlN films deposited on low pressure Mo etched more easily. Postdeposition etching of the Mo surface in Ar rf discharge prior to deposition of the AlN film was found to influence the formation of AlN residuals that were difficult to etch. Optimal rf plasma etching conditions were found, which minimized the formation of these residuals.« less
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