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Title: Atomistic Simulations of Epitaxial Recrystallization in 4H-SiC along the [0001] Direction

Abstract

Molecular dynamics (MD) methods have been employed to study the epitaxail recrystallization and amorphous-to-crystalline (a-c) transition in 4H-SiC, with simulation times of up to a few hundred ns and at temperatures of 1500 and 2000 K. Three nano-sized amorphous layers with the normal of a-c interfaces along the [-12-10 ], [-1010] and [0001] directions, respectively, were created within a crystalline cell to investigate the anisotropies of recrystallization processes. The recovery of bond defects at the interfaces is an important process driving the initial epitaxial recrystallization of the amorphous layers. The amorphous layers with the a-c interface normal along the [-12-10] direction can be completely recrystallized at the temperatures of 1500 and 2000 K, and along the [0001] direction at 2000 K. However, the recrystallized region is defected with dislocations and stacking faults. The temperatures required for complete recrystallization are in good agreement with those observed in experiments. On the other hand, the recrystallization processes for the a-c interface normal along [-1010] direction are hindered by the nucleation of polycrystalline phases. These secondary ordered phases have been identified as 4H- and 3C-SiC with different crystallographic orientations to the original 4H-SiC. The bond mismatches at the interfaces between different microcrystals result inmore » the formation of a number of stacking faults. The temperature is an important parameter to control the nucleation of the secondary ordered phase, whereas the size of amorphous region has a significant effect on their growth. These results are in good agreement with the previous experimental observations.« less

Authors:
; ; ; ;
Publication Date:
Research Org.:
Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
Sponsoring Org.:
USDOE
OSTI Identifier:
901164
Report Number(s):
PNNL-SA-50913
17292; KC0201020; TRN: US200713%%74
DOE Contract Number:  
AC05-76RL01830
Resource Type:
Journal Article
Resource Relation:
Journal Name: Nuclear Instruments and Methods in Physics Research. Section B, Beam Interactions with Materials and Atoms, 255(1):136-140; Journal Volume: 255; Journal Issue: 1
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; SILICON CARBIDES; HYDRATES; DISLOCATIONS; NUCLEATION; RECRYSTALLIZATION; STACKING FAULTS; MOLECULAR DYNAMICS METHOD; EPITAXY; PHASE TRANSFORMATIONS; Defects; Nano-Sized Amorphous Layer; Annealing Simulations; 4H-SiC; Environmental Molecular Sciences Laboratory

Citation Formats

Gao, Fei, Zhang, Yanwen, Devanathan, Ram, Posselt, Matthias, and Weber, William J. Atomistic Simulations of Epitaxial Recrystallization in 4H-SiC along the [0001] Direction. United States: N. p., 2007. Web. doi:10.1016/j.nimb.2006.11.016.
Gao, Fei, Zhang, Yanwen, Devanathan, Ram, Posselt, Matthias, & Weber, William J. Atomistic Simulations of Epitaxial Recrystallization in 4H-SiC along the [0001] Direction. United States. doi:10.1016/j.nimb.2006.11.016.
Gao, Fei, Zhang, Yanwen, Devanathan, Ram, Posselt, Matthias, and Weber, William J. Fri . "Atomistic Simulations of Epitaxial Recrystallization in 4H-SiC along the [0001] Direction". United States. doi:10.1016/j.nimb.2006.11.016.
@article{osti_901164,
title = {Atomistic Simulations of Epitaxial Recrystallization in 4H-SiC along the [0001] Direction},
author = {Gao, Fei and Zhang, Yanwen and Devanathan, Ram and Posselt, Matthias and Weber, William J.},
abstractNote = {Molecular dynamics (MD) methods have been employed to study the epitaxail recrystallization and amorphous-to-crystalline (a-c) transition in 4H-SiC, with simulation times of up to a few hundred ns and at temperatures of 1500 and 2000 K. Three nano-sized amorphous layers with the normal of a-c interfaces along the [-12-10 ], [-1010] and [0001] directions, respectively, were created within a crystalline cell to investigate the anisotropies of recrystallization processes. The recovery of bond defects at the interfaces is an important process driving the initial epitaxial recrystallization of the amorphous layers. The amorphous layers with the a-c interface normal along the [-12-10] direction can be completely recrystallized at the temperatures of 1500 and 2000 K, and along the [0001] direction at 2000 K. However, the recrystallized region is defected with dislocations and stacking faults. The temperatures required for complete recrystallization are in good agreement with those observed in experiments. On the other hand, the recrystallization processes for the a-c interface normal along [-1010] direction are hindered by the nucleation of polycrystalline phases. These secondary ordered phases have been identified as 4H- and 3C-SiC with different crystallographic orientations to the original 4H-SiC. The bond mismatches at the interfaces between different microcrystals result in the formation of a number of stacking faults. The temperature is an important parameter to control the nucleation of the secondary ordered phase, whereas the size of amorphous region has a significant effect on their growth. These results are in good agreement with the previous experimental observations.},
doi = {10.1016/j.nimb.2006.11.016},
journal = {Nuclear Instruments and Methods in Physics Research. Section B, Beam Interactions with Materials and Atoms, 255(1):136-140},
number = 1,
volume = 255,
place = {United States},
year = {Fri Feb 16 00:00:00 EST 2007},
month = {Fri Feb 16 00:00:00 EST 2007}
}