Coherent gamma-Al2O3/Ga2O3 superlattices grown on MgAl2O4 (Conference Presentation)

Takayoshi Oshima

doi:10.1117/12.2515331

8 March 2019 Coherent gamma-Al₂O₃/Ga₂O₃ superlattices grown on MgAl₂O₄ (Conference Presentation)

Takayoshi Oshima

Proceedings Volume 10919, Oxide-based Materials and Devices X; 109190G (2019) https://doi.org/10.1117/12.2515331
Event: SPIE OPTO, 2019, San Francisco, California, United States

Abstract

The rising momentum of research and developments on Ga2O3 has broaden the area of material exploration even for metastable phases. In the field of metastable Ga2O3, we have focused on defective-spinel-structured γ-phase and established some milestones: epitaxial stabilization of single crystalline films on MgAl2O4 [T. Oshima,et al., J. Cryst. Growth 359, 60 (2012).], carrier generation by impurity doping [T. Oshima et al., J. Cryst. Growth 421, 23 (2015).], and band-gap engineering by alloying γ-Al2O3 [T. Oshima et al., Appl. Phys. Express 10, 051104 (2017).]. We consider their results endorse further semiconductor engineering studies on γ-Ga2O3-related materials. Therefore, as a successive study, we have attempted to fabricate first γ-(AlxGa1−x)2O3-based heterostructures, particularly the superlattices (SLs) comprised with the end members of the alloy, to consider the possibility of obtaining coherent heterojunctions for future heterojunction device applications. 10-period γ-Al2O3/Ga2O3 SLs on (001) MgAl2O4 substrate were fabricated by plasma-assisted molecular beam epitaxy. By controlling the each layer thickness, we tuned the average Al composition (x_ave) of the coherent SLs from 0.26 to 0.86, and obtained nearly-lattice-matched SLs to the substrate at x_ave ~ 0.5. The lattice-matched SLs maintained coherent interfaces up to a period length of 7.2 nm (3.2/4.0 nm for γ-Al2O3/Ga2O3 layers) in spite of a large lattice mismatch between the end members (−3.6%). These successful fabrication of γ-Al2O3/Ga2O3 SLs means wide flexibility in designing γ-(AlxGa1−x)2O3-based heterostructures including superlattices for future development of functional heterojunction devices.

Conference Presentation

Citation Download Citation

Takayoshi Oshima "Coherent gamma-Al₂O₃/Ga₂O₃ superlattices grown on MgAl₂O₄ (Conference Presentation)", Proc. SPIE 10919, Oxide-based Materials and Devices X, 109190G (8 March 2019); https://doi.org/10.1117/12.2515331

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available