Ultra-high Mobility 2DEG Heterostructure Fabricate by Oxide Molecular Beam Epitaxy for Device Application

LaAlO3/SrTiO3 heterostructures with two-dimensional electron gas (2DEG) interface have been reported with remarkable electron transport properties, which is the demand for application of wide bandgap semiconductor devices in modern power electronics industries. Both LaAlO3 and SrTiO3 are stable insulators with high dielectric constants and bandgaps over 3eV, making them suitable for power electronics and transparent optical devices. The synthesis of the 2DEG interface is typically achieved through epitaxial growth by Pulsed Laser Deposition (PLD), with a lack of potential in large-area growth. The carrier performance is also limited by the crystalline quality control by PLD. This study reports a systematic fabrication and application of LaAlO3/SrTiO3 heterostructure by Oxide Molecular Beam Epitaxy (Oxide-MBE) with record high improved sheet carrier density up to 1017 1/cm2, low sheet resistivity down to 18 Ω/□ at room temperature, and ultra-high hall mobility exceeding 7.5×104 cm2/V·s at the 2DEG interface with stoichiometry perfect crystalline structure. The samples with the film thickness of less than 10 UC were integrated into rectifier devices and illustrated a stable rectification process with a breakdown voltage exceeding the measuring limit for the conductive Atomic Force Microscopy platinum tip, illustrating a significant potential application of small-size power electronic devices. The thermal transport performance is studied and the ultra-high thermal conductivity agrees on the high potential of application in modern power electronics. This study explores a pathway for future large-scale epitaxial growth for LaAlO3/SrTiO3 with Oxide-MBE with industry-level electron performance and provides a systematic approach for wide bandgap microelectronic semiconductor integration.

Grantor dc:publisher

UNSW, Sydney

Year dc:date

2024

Author dc:creator

• Wang, David

Statement dc:rights

• embargoed access
• CC BY 4.0

Licence

• http://purl.org/coar/access_right/c_f1cf
• https://creativecommons.org/licenses/by/4.0/

Language dc:language

en

Identifier

https://doi.org/10.26190/unsworks/30607

OAI identifier oai:identifier

oai:unsworks.library.unsw.edu.au:1959.4/103341