N-type dopants in (001) β-Ga2O3 grown on (001) β-Ga2O3 substrates by plasma-assisted molecular beam epitaxy. (1st March 2018)

• Record Type: Journal Article
• Authors: Han, Sang-Heon; Mauze, Akhil; Ahmadi, Elaheh; Mates, Tom; Oshima, Yuichi; Speck, James S
• Is Part Of: Semiconductor science and technology. Volume 33:Number 4(2018:Apr.)
• Publication Date: 2018-03-01
• Subjects: β-Ga2O3 -- oxides -- molecular beam epitaxy -- wide-bandgap semiconductor; Semiconductors -- Periodicals; 621.38152
• DOI: 10.1088/1361-6641/aaae56
• Languages: English
• ISSNs: 0268-1242

Abstract

Abstract: Ge and Sn as n -type dopants in (001) β -Ga2 O3 films were investigated using plasma-assisted molecular beam epitaxy. The Ge concentration showed a strong dependence on the growth temperature, whereas the Sn concentration remains independent of the growth temperature. The maximum growth temperature at which a wide range of Ge concentrations (from 10 17 to 10 20 cm −3 ) could be achieved was 675 °C while the same range of Sn concentration could be achieved at growth temperature of 750 °C. Atomic force microscopy results revealed that higher growth temperature shows better surface morphology. Therefore, our study reveals a tradeoff between higher Ge doping concentration and high quality surface morphology on (001) β -Ga2 O3 films grown by plasma-assisted molecular beam epitaxy. The Ge doped films had an electron mobility of 26.3 cm 2 V −1 s −1 at the electron concentration of 6.7 × 10 17 cm −3 whereas the Sn doped films had an electron mobility of 25.3 cm 2 V −1 s −1 at the electron concentration of 1.1 × 10 18 cm −3 .