Epitaxial Growth of β-Ga₂O₃ Thin Films on Si with YSZ Buffer Layer

Abstract

We report the epitaxial growth of (2̅01)-oriented β-Ga2O3 thin films on a (001) Si substrate using the pulsed laser deposition technique employing epitaxial yttria-stabilized zirconia (YSZ) buffer layers. Epitaxial β-Ga2O3 thin films possess a biaxial compressive strain on YSZ single-crystal substrates while they exhibit a biaxial tensile strain on YSZ-buffered Si substrates. Post-annealing improves the crystalline quality of β-Ga2O3 thin films. High-resolution X-ray diffraction analyses reveal that the epitaxial (2̅01) β-Ga2O3 thin films on Si have eight in-plane domain variants to accommodate the large difference in the crystal structure between monoclinic β-Ga2O3 and cubic YSZ. The results provide a pathway to integrate epitaxial β-Ga2O3 thin films on a Si gold standard substrate, which will expand the application scope beyond high-power electronics.

Low Interface Resistance in Epitaxial β-Ga2O3 Vertical Power Diodes on Silicon (100) Using TiN Buffer

“…In addition, Ga 2 O 3 is thermodynamically unstable on Si, reducing to Ga and SiO 2 . − We need a stable buffer to successfully integrate epitaxial Ga 2 O 3 on Si. Epitaxial β-Ga 2 O 3 (2̅01) on Si (001) has been demonstrated with γ-Al 2 O 3 and YSZ buffer using molecular beam epitaxy (MBE) and pulsed laser deposition (PLD), respectively. We (Vura et al) have previously demonstrated β-Ga 2 O 3 (400) on Si (100) using MgO buffer for deep UV photodetectors.…”