Molecular beam homoepitaxy of N-polar AlN on bulk AlN substrates
Abstract
N-polar AlN epilayers were grown on the N-face of single-crystal bulk AlN substrates by plasma-assisted molecular beam epitaxy. A combination of in situ thermal deoxidation and Al-assisted thermal desorption at high temperature aided in removing native surface oxides and impurities from the N-polar surface of the substrate enabling successful homoepitaxy. Subsequent epitaxial growth of the AlN layer on the in situ cleaned substrates, grown in a 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 impurity concentrations of ∼8×1017 and ∼2×1017 atoms/cm3 are observed, respectively. Although the structural defect densities are low, they interestingly appear as inversion domains of different dimensionalities.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Sep 01, 2022
- Source ID
- 10.1063/5.0100225
Entities
People
- Debdeep Jena
- Huili Grace Xing
- Jashan Singhal
- Jimy Encomendero Risco
- Kazuki Nomoto
- Len van Deurzen
- Masato Toita
- Yong-Jin Cho
- Zexuan Zhang
Organizations
- Air Force Office of Scientific Research
- Asahi Kasei
- Cornell University
- National Science Foundation
- Semiconductor Research Corporation
- United States Department of Energy