Energy-driven multi-step structural phase transition mechanism to achieve high-quality p-type nitrogen-doped β-Ga2O3 films. (March 2021)

• Record Type: Journal Article
• Authors: Wu, Z.Y.; Jiang, Z.X.; Ma, C.C.; Ruan, W.; Chen, Y.; Zhang, H.; Zhang, G.Q.; Fang, Z.L.; Kang, J.Y.; Zhang, T.-Y.
• Is Part Of: Materials today physics. Volume 17(2021)
• Publication Date: 2021-03
• Subjects: Gallium oxide -- p-type conductivity and stability -- Multi-step structural phase transition -- Nitrogen acceptor -- Field effect transistor; Materials science -- Periodicals; Physics -- Periodicals; Electronic journals; 530.41
• DOI: 10.1016/j.mtphys.2021.100356
• Languages: English
• ISSNs: 2542-5293

Abstract

Abstract: It is a big challenge to grow β-Ga2 O3 films of good p-type conductivity and stability due to the large acceptor ionization energy, strong hole-trapping effect, low hole mobility, and self-compensation effects. In this study, we demonstrate for the first time the success in the growth of high-quality p-type N-doped β-Ga2 O3 films with an acceptor ionization energy of 0.165 eV, Hall resistivity of 17.0 Ωcm, Hall hole mobility of 23.6 cm 2 V −1 s −1, hole concentration of 1.56 × 10 16 cm −3 and good stability, and in the fabrication of high-performance p-type β-Ga2 O3 films-based field effect transistors. The success paves the way to fabricate full β-Ga2 O3 films based p-n diodes and will advance the applications of next-generation high-performance β-Ga2 O3 -based optoelectronic and electronic devices. In addition, we discover the growth mechanism of multi-step structural phase transitions from hexagonal P63 mc GaN to rhombohedral R 3 ¯ c α-GaNx O3(1-x)/2 and finally to monolithic C2/m N-doped β-Ga2 O3, which improves the crystalline quality, facilitates the acceptor doping, increases the acceptor activation efficiency, and thus enhances the p-type conductivity and stability of the N-doped β-Ga2 O3 films. The novel p-type oxide film growth technique and mechanism open a new horizon to the other wide bandgap oxide semiconductors. Graphical abstract: Image 1 Highlights: Discover energy-driven multi-step structural phase transition mechanism. Achieve N-doped β-Ga2 O3 films with good p-type conductivity and stability. Fabricate high-performance p-type β-Ga2 O3 films-based field effect transistors. Advance development of full β-Ga2 O3 based optoelectronic and electronic devices. Open a new horizon to the other wide bandgap oxide semiconductors.