Molecular Beam Homoepitaxy of N-polar AlN on bulk AlN substrates

Fuente: arXiv
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Bibliographic Details
Main Authors: Singhal, Jashan, Encomendero, Jimy, Cho, Yongjin, van Deurzen, Len, Zhang, Zexuan, Nomoto, Kazuki, Toita, Masato, Xing, Huili Grace, Jena, Debdeep
Format: Preprint
Published: 2022
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author Singhal, Jashan
Encomendero, Jimy
Cho, Yongjin
van Deurzen, Len
Zhang, Zexuan
Nomoto, Kazuki
Toita, Masato
Xing, Huili Grace
Jena, Debdeep
author_facet Singhal, Jashan
Encomendero, Jimy
Cho, Yongjin
van Deurzen, Len
Zhang, Zexuan
Nomoto, Kazuki
Toita, Masato
Xing, Huili Grace
Jena, Debdeep
contents N-polar AlN epilayers were grown on the N-face of single crystal bulk AlN substrates by plasma assisted molecular beam epitaxy (PA-MBE). A combination of in situ thermal deoxidation and Al-assisted thermal desorption at high temperature helped in removing native surface oxides and impurities from the N-polar surface of the substrate enabling successful homoepitaxy. Subsequent epitaxial growth of AlN layer on the in situ cleaned substrates, grown in sufficiently high Al droplet regime, exhibited smooth surface morphologies with clean and wide atomic steps. KOH etch studies confirmed the N-polarity of the homoepitaxial films. Secondary ion mass spectrometry profiles show Si and H impurity concentrations below the noise levels, whereas O and C impurities concentrations of ~ 8x10^{17} atoms/cm^3 and ~ 2x10^{17} atoms/cm^3 are observed respectively. Though the structural defect densities are low, they interestingly appear as inversion domains of different dimensionalities.
format Preprint
id arxiv_https___arxiv_org_abs_2206_11370
institution arXiv
publishDate 2022
record_format arxiv
spellingShingle Molecular Beam Homoepitaxy of N-polar AlN on bulk AlN substrates
Singhal, Jashan
Encomendero, Jimy
Cho, Yongjin
van Deurzen, Len
Zhang, Zexuan
Nomoto, Kazuki
Toita, Masato
Xing, Huili Grace
Jena, Debdeep
Materials Science
N-polar AlN epilayers were grown on the N-face of single crystal bulk AlN substrates by plasma assisted molecular beam epitaxy (PA-MBE). A combination of in situ thermal deoxidation and Al-assisted thermal desorption at high temperature helped in removing native surface oxides and impurities from the N-polar surface of the substrate enabling successful homoepitaxy. Subsequent epitaxial growth of AlN layer on the in situ cleaned substrates, grown in sufficiently high Al droplet regime, exhibited smooth surface morphologies with clean and wide atomic steps. KOH etch studies confirmed the N-polarity of the homoepitaxial films. Secondary ion mass spectrometry profiles show Si and H impurity concentrations below the noise levels, whereas O and C impurities concentrations of ~ 8x10^{17} atoms/cm^3 and ~ 2x10^{17} atoms/cm^3 are observed respectively. Though the structural defect densities are low, they interestingly appear as inversion domains of different dimensionalities.
title Molecular Beam Homoepitaxy of N-polar AlN on bulk AlN substrates
topic Materials Science
url https://arxiv.org/abs/2206.11370