Metalorganic Chemical Vapor Deposition of $Ga_2O_3$ Thin Films Using Dimethylgallium Isopropoxide and $O_2$

  • 우정준 (고려대학교 소재화학과) ;
  • 박영수 (고려대학교 신소재화학과) ;
  • 이희주 (고려대학교 소재화학과) ;
  • 전두진 (고려대학교 소재화학과) ;
  • 김건희 (고려대학교 소재화학과) ;
  • 김윤수 (고려대학교 신소재화학과)
  • 발행 : 2010.02.17

초록

$Ga_2O_3$ thin films have been grown on Si(001) substrates by metalorganic chemical vapor deposition (MOCVD) using dimethylgallium isopropoxide ($Me_2GaO^iPr$, DMGIP) with oxygen as the reactant gas. Suitability of the precursor for CVD was confirmed by thermogravimetric analysis (TGA) and vapor pressure measurement. Deposition was carried out in the substrate temperature range $450-650^{\circ}C$. Spectroscopic ellipsometry, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) and Rutherford back-scattering spectroscopy (RBS) were used to determine the thickness, crystallinity, and composition and stoichiometry of the films, respectively. From the slope of the Arrhenius plot in the temperature range $500-550^{\circ}C$, the activation energy of deposition was found to be $225.5\;kJ\;mol^{-1}$. As-deposited films were amorphous, but the monoclinic $\beta-Ga_2O_3$ phase was revealed after annealing the films in air at $1050^{\circ}C$. The XPS and RBS analyses indicate that the $Ga_2O_3$ films obtained by using DMGIP were found to be almost stoichiometric.

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