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Title: Real-time synchrotron x-ray studies of low- and high-temperature nitridation of c-plane sapphire

Abstract

The plasma nitridation kinetics of c-plane sapphire at both low (200-300 deg. C) and high (750 deg. C) substrate temperatures was examined using grazing-incidence real-time x-ray diffraction, in situ x-ray reflection and in situ reflection high-energy electron diffraction (RHEED). These monitored the evolution of the nitride thickness, strain, and surface structure during nitridation. The evolution of the AlN(1010) peak showed that the heteroepitaxial strain in the first layer of nitride is already significantly relaxed relative to the substrate. Subsequent layers grow with increasing relaxation. In both the high- and low-temperature nitridation cases, the results suggest that the early stage nitridation is governed by a complex nucleation and growth process. Nitridation at both temperatures apparently proceeds in a two-dimensional growth mode with the initial nucleating islands consisting of several monolayers which grow laterally. At low temperature the growth slows or even stops after impingement of the nucleating islands covering the surface, possibly due to low diffusivities through the existing layer. Initial formation and growth rates of nucleating islands at high temperatures are comparable to those at low temperatures, but subsequent growth into the substrate is significantly enhanced over the low temperature case, consistent with activation energies of 0.1-0.25 eV.

Authors:
; ;  [1];  [2]; ;  [3]; ;  [4];  [5]
  1. Physics Department, Boston University, Boston, Massachusetts 02215 (United States)
  2. Department of Aerospace and Mechanical Engineering, Boston University, Boston, Massachusetts 02215 (United States)
  3. Department of Electrical and Computer Engineering, Boston University, Boston, Massachusetts 02215 (United States)
  4. Department of Physics, University of Vermont, Burlington, Vermont 05405 (United States)
  5. National Synchrotron Light Source, Brookhaven National Laboratory, Upton, New York 11973 (United States)
Publication Date:
OSTI Identifier:
20853973
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. B, Condensed Matter and Materials Physics; Journal Volume: 74; Journal Issue: 23; Other Information: DOI: 10.1103/PhysRevB.74.235304; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ACTIVATION ENERGY; ALUMINIUM NITRIDES; DIFFUSION; ELECTRON DIFFRACTION; EPITAXY; EV RANGE; EVOLUTION; KINETICS; LAYERS; NITRIDATION; NUCLEATION; PLASMA; REFLECTION; RELAXATION; SAPPHIRE; SEMICONDUCTOR MATERIALS; STRAINS; SUBSTRATES; SURFACES; TEMPERATURE DEPENDENCE; X RADIATION; X-RAY DIFFRACTION

Citation Formats

Wang Yiyi, Oezcan, Ahmet S., Ludwig, Karl F. Jr., Oezaydin, Goezde, Bhattacharyya, Anirban, Moustakas, Theodore D., Zhou, Hua, Headrick, Randall L., and Siddons, D. Peter. Real-time synchrotron x-ray studies of low- and high-temperature nitridation of c-plane sapphire. United States: N. p., 2006. Web. doi:10.1103/PHYSREVB.74.235304.
Wang Yiyi, Oezcan, Ahmet S., Ludwig, Karl F. Jr., Oezaydin, Goezde, Bhattacharyya, Anirban, Moustakas, Theodore D., Zhou, Hua, Headrick, Randall L., & Siddons, D. Peter. Real-time synchrotron x-ray studies of low- and high-temperature nitridation of c-plane sapphire. United States. doi:10.1103/PHYSREVB.74.235304.
Wang Yiyi, Oezcan, Ahmet S., Ludwig, Karl F. Jr., Oezaydin, Goezde, Bhattacharyya, Anirban, Moustakas, Theodore D., Zhou, Hua, Headrick, Randall L., and Siddons, D. Peter. Fri . "Real-time synchrotron x-ray studies of low- and high-temperature nitridation of c-plane sapphire". United States. doi:10.1103/PHYSREVB.74.235304.
@article{osti_20853973,
title = {Real-time synchrotron x-ray studies of low- and high-temperature nitridation of c-plane sapphire},
author = {Wang Yiyi and Oezcan, Ahmet S. and Ludwig, Karl F. Jr. and Oezaydin, Goezde and Bhattacharyya, Anirban and Moustakas, Theodore D. and Zhou, Hua and Headrick, Randall L. and Siddons, D. Peter},
abstractNote = {The plasma nitridation kinetics of c-plane sapphire at both low (200-300 deg. C) and high (750 deg. C) substrate temperatures was examined using grazing-incidence real-time x-ray diffraction, in situ x-ray reflection and in situ reflection high-energy electron diffraction (RHEED). These monitored the evolution of the nitride thickness, strain, and surface structure during nitridation. The evolution of the AlN(1010) peak showed that the heteroepitaxial strain in the first layer of nitride is already significantly relaxed relative to the substrate. Subsequent layers grow with increasing relaxation. In both the high- and low-temperature nitridation cases, the results suggest that the early stage nitridation is governed by a complex nucleation and growth process. Nitridation at both temperatures apparently proceeds in a two-dimensional growth mode with the initial nucleating islands consisting of several monolayers which grow laterally. At low temperature the growth slows or even stops after impingement of the nucleating islands covering the surface, possibly due to low diffusivities through the existing layer. Initial formation and growth rates of nucleating islands at high temperatures are comparable to those at low temperatures, but subsequent growth into the substrate is significantly enhanced over the low temperature case, consistent with activation energies of 0.1-0.25 eV.},
doi = {10.1103/PHYSREVB.74.235304},
journal = {Physical Review. B, Condensed Matter and Materials Physics},
number = 23,
volume = 74,
place = {United States},
year = {Fri Dec 15 00:00:00 EST 2006},
month = {Fri Dec 15 00:00:00 EST 2006}
}