Successful Growth of Conductive Highly Crystalline Sn-Doped α-Ga₂O₃ Thin Films by Fine-Channel Mist Chemical Vapor Deposition

Abstract

Highly crystalline α-phase gallium oxide (Ga 2 O 3 ) thin films were grown by fine-channel mist chemical vapor deposition on c -sapphire substrates at 400 °C at a deposition rate of more than 20 nm/min. The thin films were doped with Sn(IV) atoms, which were obtained from Sn(II) chloride by the reaction SnCl 2 + H 2 O 2 + 2HCl→SnCl 4 + 2H 2 O. Conductive α-phase Ga 2 O 3 thin films were successfully grown from source solutions containing less than 10 at. % Sn(IV). The source solution containing 4 at. % Sn(IV) resulted in obtaining a thin film with an n-type conductivity as high as 0.28 S cm -1 , a mobility of 0.23 cm 2 V -1 s -1 , a carrier concentration of 7×10 18 cm -3 , and a full width at half maximum (FWHM) of the (0006) reflection X-ray rocking curve as low as 64 arcsec.