High electron density \({\beta}-(Al_{0.18}Ga_{0.82})_2O_3/Ga_2O_3\) modulation doping using ultra-thin (1 nm) spacer layer

• Published in: arXiv.org
• Main Authors: Nidhin Kurian Kalarickal, Xia, Zhanbo, Mcglone, Joe, Liu, Yumo, Moore, Wyatt, Arehart, Aaron, Ringel, Steve, Rajan, Siddharth
• Format: Paper Journal Article
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 25.10.2019
• Subjects: Aluminum; Charge density; Doping; Electrical measurement; Electron density; Electrons; Heterojunctions; Heterostructures; Modulation; Modulation doping; Physics - Applied Physics; Physics - Materials Science; Physics - Other Condensed Matter; Silicon
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.1910.11521

We report on the design and demonstration of \({\beta}-(Al_{0.18}Ga_{0.82})_2O_3/Ga_2O_3\) modulation doped heterostructures to achieve high sheet charge density. The use of a thin spacer layer between the Si delta-doping and heterojunction interface was investigated in \({\beta}-(Al_{0.18}Ga_{0.82})_2O_3/Ga_2O_3\) modulation doped structures. We find that that this strategy enables higher 2DEG sheet charge density up to 6.1x10^12 cm^2 with mobility of 147 cm^2/Vs. The presence of a degenerate 2DEG channel was confirmed by the measurement of low temperature effective mobility of 378 cm^2/V-s and a lack of carrier freeze out from low temperature capacitance voltage measurements. The electron density of 6.1x10^12 cm^2 is the highest reported sheet charge density obtained without parallel conduction channels in an \((Al_{0.18}Ga_{0.82})_2O_3/Ga_2O_3\) heterostructure system.