Growth of β‐Ga₂O₃ on Al₂O₃ and GaAs using metal‐organic vapor‐phase epitaxy

Abstract

Epitaxial layers of monoclinic β‐Ga2O3 were successfully grown on (0001) sapphire and ($ \bar 1 $11)As GaAs substrates using metal‐organic vapor‐phase epitaxy (MOVPE). Triethylgallium (TEGa) and N2O were used as precursors for gallium and oxygen, respectively. Growth conditions could be determined, where β‐Ga2O3 grows epitaxially on c ‐plane sapphire and ($ \bar 1 $11)As GaAs substrates. X‐ray diffraction (XRD) and transmission electron microscopy (TEM) measurements identify a epitaxial relationship with ($ \bar 2 $01) β‐Ga2O3 || (0001) sapphire and ($ \bar 2 $01) β‐Ga2O3 || ($ \bar 1 $11)As GaAs. The observed sixfold rotational in‐plane symmetry results from differently oriented rotational domains of monoclinic β‐Ga2O3 with twofold symmetry. Thin films deposited on substrates of other orientation show the formation of the low‐temperature modification α‐Ga2O3. Optical transmission spectra measured in the spectral range from 200 nm to 2000 nm show a well‐distinct absorption edge at about 5 eV for layers grown on c ‐ and a ‐plane sapphire. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Quasi-heteroepitaxial growth of β-Ga2O3 on off-angled sapphire (0 0 0 1) substrates by halide vapor phase epitaxy

“…Growth of β-Ga 2 O 3 on foreign substrates has been reported on sapphire [11][12][13][14]16,17], MgO [11,15], etc. These β-Ga 2 O 3 thin-films are highly textured, exhibiting single out-of-plane orientations.…”

“…So far, several epitaxial growth techniques of β-Ga 2 O 3 , such as molecular beam epitaxy (MBE) [11][12][13], metalorganic vapor phase epitaxy (MOPVE) [14,15], and pulsed laser deposition (PLD) [16,17], have been reported. Among them, MBE is mainly used for the study of β-Ga 2 O 3 power devices [5][6][7][8].…”

Effect of growth pressure on the characteristics of β-Ga2O3 films grown on GaAs (100) substrates by MOCVD method

“…Because high quality ␤-Ga 2 O 3 substrates are hard to obtain, the ␤-Ga 2 O 3 films are usually prepared on other substrates, such as Al 2 O 3 , Si, GaAs, MgO, MgAl 2 O 4 , and GaN [1,18,[21][22][23][24][25]. Among these substrates, Ga 2 O 3 films could be grown easily on gallium-based semiconductors (such as GaAs) for the native oxide layer at their surface [26,27].…”

ALD and MOCVD of Ga2O3 Thin Films Using the New Ga Precursor Dimethylgallium Isopropoxide, Me2GaOiPr

“…ALD is also important as the sizes of electronic devices become smaller. Precursors for gallium oxide thin films include Ga(hfac) 3 , [38,56] Ga(dpm) 3 , [56] Ga(acac) 3 , [48] Ga[OCH(CF 3 ) 2 ] 3 (HNMe 2 ), [39] [ [40] Ga(O i Pr) 3 , [41] GaCl 3 , [42] Me 3 Ga, [43][44][45]49] Ga 2 (NMe 2 ) 6 , [46,50] [Me 2 GaNMe 2 ], [51,52] Ga(ROCOCHOCOR) 3 , [47] Et 3 Ga, [53] [Me 2 GaOCH 2 CH 2 NMe 2 ] 2 , 57 etc. Except for the trialkylgallium compounds, the precursors are mostly solids at room temperature and not convenient to use, although some of them readily volatilize with mild heating.…”

“…[36] Ga-doped zinc oxide (ZnO:Ga, GZO) is a wellknown n-type TCO material. [37] Thin films of gallium oxide have been prepared by various methods: (radiofrequency) magnetron sputter deposition, [1][2][3][4]6,7,9,10,12,25,27] electron beam evaporation, [15][16][17]21] pulsed laser deposition, [26,28,30,33,34,36] laser ablation, [31] CVD, [38][39][40][41][42][43][44][45][46][47] ALD, [48][49][50][51][52] molecular beam epitaxy, [32,35] vapor phase epitaxy, [53] spray pyrolysis, [54,55] and sol-gel process. [5,13,23,24] Among these methods, CVD is considered very important because it can readily be employed in industrial processes.…”