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Title: Real-time growth study of plasma assisted atomic layer epitaxy of InN films by synchrotron x-ray methods

Abstract

The temporal evolution of high quality indium nitride (InN) growth by plasma-assisted atomic layer epitaxy (ALEp) on a-plane sapphire at 200 and 248 °C was probed by synchrotron x-ray methods. The growth was carried out in a thin film growth facility installed at beamline X21 of the National Synchrotron Light Source at Brookhaven National Laboratory and at beamline G3 of the Cornell High Energy Synchrotron Source, Cornell University. Measurements of grazing incidence small angle x-ray scattering (GISAXS) during the initial cycles of growth revealed a broadening and scattering near the diffuse specular rod and the development of scattering intensities due to half unit cell thick nucleation islands in the Yoneda wing with correlation length scale of 7.1 and 8.2 nm, at growth temperatures (Tg) of 200 and 248 °C, respectively. At about 1.1 nm (two unit cells) of growth thickness nucleation islands coarsen, grow, and the intensity of correlated scattering peak increased at the correlation length scale of 8.0 and 8.7 nm for Tg = 200 and 248 °C, respectively. The correlated peaks at both growth temperatures can be fitted with a single peak Lorentzian function, which support single mode growth. Post-growth in situ x-ray reflectivity measurements indicate a growthmore » rate of ~0.36 Å/cycle consistent with the growth rate previously reported for self-limited InN growth in a commercial ALEp reactor. Consistent with the in situ GISAXS study, ex situ atomic force microscopy power spectral density measurements also indicate single mode growth. Electrical characterization of the resulting film revealed an electron mobility of 50 cm2/V s for a 5.6 nm thick InN film on a-plane sapphire, which is higher than the previously reported mobility of much thicker InN films grown at higher temperature by molecular beam epitaxy directly on sapphire. These early results indicated that in situ synchrotron x-ray study of the epitaxial growth kinetics of InN films is a very powerful method to understand nucleation and growth mechanisms of ALEp to enable improvement in material quality and broaden its application.« less

Authors:
 [1];  [2];  [1];  [1];  [1];  [3];  [4];  [3];  [1]
  1. U.S. Naval Research Laboratory, 4555 Overlook Avenue SW, Washington, DC 20375
  2. American Society for Engineering Education, 1818 N Street NW, Washington, DC 20036
  3. Physics Department, Boston University, 590 Commonwealth Avenue, Boston, Massachusetts 02215
  4. Department of Physics, SUNY College at Brockport, 350 New Campus Dr, Brockport, New York 14420
Publication Date:
Research Org.:
Brookhaven National Laboratory (BNL), Upton, NY (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1409593
Report Number(s):
BNL-114645-2017-JA¿¿¿
Journal ID: ISSN 0734-2101; JVTAD6
DOE Contract Number:  
SC0012704
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Vacuum Science and Technology. A, Vacuum, Surfaces and Films; Journal Volume: 35; Journal Issue: 3
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE

Citation Formats

Nepal, Neeraj, Anderson, Virginia R., Johnson, Scooter D., Downey, Brian P., Meyer, David J., DeMasi, Alexander, Robinson, Zachary R., Ludwig, Karl F., and Eddy, Charles R.. Real-time growth study of plasma assisted atomic layer epitaxy of InN films by synchrotron x-ray methods. United States: N. p., 2017. Web. doi:10.1116/1.4978026.
Nepal, Neeraj, Anderson, Virginia R., Johnson, Scooter D., Downey, Brian P., Meyer, David J., DeMasi, Alexander, Robinson, Zachary R., Ludwig, Karl F., & Eddy, Charles R.. Real-time growth study of plasma assisted atomic layer epitaxy of InN films by synchrotron x-ray methods. United States. doi:10.1116/1.4978026.
Nepal, Neeraj, Anderson, Virginia R., Johnson, Scooter D., Downey, Brian P., Meyer, David J., DeMasi, Alexander, Robinson, Zachary R., Ludwig, Karl F., and Eddy, Charles R.. Mon . "Real-time growth study of plasma assisted atomic layer epitaxy of InN films by synchrotron x-ray methods". United States. doi:10.1116/1.4978026.
@article{osti_1409593,
title = {Real-time growth study of plasma assisted atomic layer epitaxy of InN films by synchrotron x-ray methods},
author = {Nepal, Neeraj and Anderson, Virginia R. and Johnson, Scooter D. and Downey, Brian P. and Meyer, David J. and DeMasi, Alexander and Robinson, Zachary R. and Ludwig, Karl F. and Eddy, Charles R.},
abstractNote = {The temporal evolution of high quality indium nitride (InN) growth by plasma-assisted atomic layer epitaxy (ALEp) on a-plane sapphire at 200 and 248 °C was probed by synchrotron x-ray methods. The growth was carried out in a thin film growth facility installed at beamline X21 of the National Synchrotron Light Source at Brookhaven National Laboratory and at beamline G3 of the Cornell High Energy Synchrotron Source, Cornell University. Measurements of grazing incidence small angle x-ray scattering (GISAXS) during the initial cycles of growth revealed a broadening and scattering near the diffuse specular rod and the development of scattering intensities due to half unit cell thick nucleation islands in the Yoneda wing with correlation length scale of 7.1 and 8.2 nm, at growth temperatures (Tg) of 200 and 248 °C, respectively. At about 1.1 nm (two unit cells) of growth thickness nucleation islands coarsen, grow, and the intensity of correlated scattering peak increased at the correlation length scale of 8.0 and 8.7 nm for Tg = 200 and 248 °C, respectively. The correlated peaks at both growth temperatures can be fitted with a single peak Lorentzian function, which support single mode growth. Post-growth in situ x-ray reflectivity measurements indicate a growth rate of ~0.36 Å/cycle consistent with the growth rate previously reported for self-limited InN growth in a commercial ALEp reactor. Consistent with the in situ GISAXS study, ex situ atomic force microscopy power spectral density measurements also indicate single mode growth. Electrical characterization of the resulting film revealed an electron mobility of 50 cm2/V s for a 5.6 nm thick InN film on a-plane sapphire, which is higher than the previously reported mobility of much thicker InN films grown at higher temperature by molecular beam epitaxy directly on sapphire. These early results indicated that in situ synchrotron x-ray study of the epitaxial growth kinetics of InN films is a very powerful method to understand nucleation and growth mechanisms of ALEp to enable improvement in material quality and broaden its application.},
doi = {10.1116/1.4978026},
journal = {Journal of Vacuum Science and Technology. A, Vacuum, Surfaces and Films},
number = 3,
volume = 35,
place = {United States},
year = {Mon Mar 13 00:00:00 EDT 2017},
month = {Mon Mar 13 00:00:00 EDT 2017}
}