Laser CVD Growth of Uniquely <010>‐oriented β‐Ga₂O₃ Films on Quartz Substrate with Ultrafast Photoelectric Response

Abstract The oriented growth of β‐Ga₂O₃ films has triggered extensive interest due to the remarkable and complex anisotropy found in the β‐Ga₂O₃ bulks. Remarkable properties, including stronger solar‐blind ultraviolet (SBUV) absorption, better mobility, and higher thermal conductivity, are usually observed along <010> direction as compared to other low‐index axes. So far, <010>‐oriented β‐Ga₂O₃ film growth has been hindered by the lack of suitable substrates and higher surface energy of the (010) crystal plane. Herein, the first growth of uniquely <010>‐oriented β‐Ga₂O₃ films on quartz substrates by laser chemical vapor deposition (LCVD) are reported. By investigating the effects of deposition temperature (T_dep) and O₂ flow rate (R_O2) on the growth of β‐Ga₂O₃ films, it is found that the formation of <010> orientation is closely related to the higher stability of oxygen close‐packed planes under O‐rich condition. As a result, a grain size of up to ≈2 µm and a deposition rate of up to ≈ 40 µm h⁻¹ are obtained. Metal‐semiconductor‐metal (MSM) type detector based on <010>‐oriented β‐Ga₂O₃ film exhibits ultra‐fast response speed, 1–2 orders of magnitude higher than those of most detectors based on β‐Ga₂O₃ films with other orientations.