| Title: |
Growth of a-plane BaTiO3 on a-plane β-Ga2O3 by molecular-beam epitaxy |
| Authors: |
Kathy Azizie; Naomi A. Pieczulewski; Nicholas A. Parker; Jian V. Li; Nolan S. Hendricks; Kyle J. Liddy; Yorick A. Birkhölzer; Eric A. Welp; Luke Omodt; Thaddeus J. Asel; Shin Mou; David A. Muller; Darrell G. Schlom |
| Source: |
APL Materials, Vol 14, Iss 1, Pp - (2026) |
| Publisher Information: |
AIP Publishing LLC, 2026. |
| Publication Year: |
2026 |
| Collection: |
LCC:Biotechnology; LCC:Physics |
| Subject Terms: |
Biotechnology; TP248.13-248.65; Physics; QC1-999 |
| Description: |
We demonstrate the epitaxial growth of single-phase (100) BaTiO3 films on (100) β-Ga2O3 substrates at substrate temperatures ranging from 600 to 700 °C using molecular-beam epitaxy. Characterization of a 47 nm thick BaTiO3 film by atomic force microscopy reveals a step-and-terrace morphology with unit-cell-high BaTiO3 steps and an rms surface roughness of 0.26 nm. Scanning transmission electron microscopy (STEM) images show that in some regions the β-Ga2O3 substrate terminates with a (100)A plane as it transitions to BaTiO3 and in other regions with a (100)B plane. The (100) BaTiO3 films are fully relaxed and consist of a mixture of two types of a-axis domains: a1 and a2. The orientation relationship determined by X-ray diffraction and confirmed by STEM is (100) BaTiO3 || (100) β-Ga2O3 and [011] BaTiO3||[010] β-Ga2O3. Despite the average linear lattice mismatch of 3.8%, BaTiO3 films with rocking curve full width at half maximum widths as narrow as 28 arc sec are achieved. From capacitance–voltage measurements on a metal–oxide–semiconductor capacitor structure with a-axis BaTiO3 as the oxide layer and Si-doped β-Ga2O3 as the semiconducting layer, we extract a dielectric constant of K11 = 670 for the BaTiO3 epitaxially integrated with (100) β-Ga2O3. We anticipate that this high-K epitaxial dielectric will be useful for electric-field management in β-Ga2O3-based device structures. |
| Document Type: |
article |
| File Description: |
electronic resource |
| Language: |
English |
| ISSN: |
2166-532X |
| Relation: |
https://doaj.org/toc/2166-532X |
| DOI: |
10.1063/5.0302145/20877490/011110_1_5.0302145.pdf |
| DOI: |
10.1063/5.0302145 |
| Access URL: |
https://doaj.org/article/7fac54b67e4e4c2ebfba24db033c4c70 |
| Accession Number: |
edsdoj.7fac54b67e4e4c2ebfba24db033c4c70 |
| Database: |
Directory of Open Access Journals |