Molecular beam homoepitaxy of N-polar AlN: Enabling role of aluminum-assisted surface cleaning
Abstract
N-polar aluminum nitride (AlN) is an important building block for next-generation high-power radio frequency electronics. We report successful homoepitaxial growth of N-polar AlN by molecular beam epitaxy (MBE) on large-area, cost-effective N-polar AlN templates. Direct growth without any in situ surface cleaning leads to films with inverted Al polarity. It is found that Al-assisted cleaning before growth enables the epitaxial film to maintain N-polarity. The grown N-polar AlN epilayer with its smooth, pit-free surface duplicates the structural quality of the substrate, as evidenced by a clean and smooth growth interface with no noticeable extended defects generation. Near band-edge photoluminescence peaks are observed at room temperature on samples with MBE-grown layers but not on the bare AlN templates, implying the suppression of nonradiative recombination centers in the epitaxial N-polar AlN.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Sep 09, 2022
- Source ID
- 10.1126/sciadv.abo6408
Entities
People
- Akira Sakai
- Debdeep Jena
- Hideto Miyake
- Huili Grace Xing
- Jashan Singhal
- Tetsuya Tohei
- Vladimir Protasenko
- Yong-Jin Cho
- Yusuke Hayashi
- Zexuan Zhang
Organizations
- Cornell University
- Mie University
- Osaka University