Epitaxial $\beta$ -Ga2O3 and $\beta$ -(AlxGa1−x)2O3/ $\beta$ -Ga2O3 Heterostructures Growth for Power Electronics

We report on the growth of high quality β-Ga
₂
O
₃
films using metal organic chemical vapor deposition (MOCVD). Ga(DPM)
₃
, TEGa, and TMGa metal organic precursors were used as Ga sources and oxygen for oxidation. Films grown from each Ga sources had high growth rates with up to 10 μm/h achieved using TMGa. To study the quality homoepitaxial layers, MOCVD was used to grow unintentionally doped (UID) and Si doped β-Ga
₂
O
₃
layers with a growth rate between 0.5 and 4.0 μm/h Epitaxial layers with XRD FWHM and RMS roughness <; 50 arcsec and <; 0.5 nm, respectively, were demonstrated. The electron mobility increased from ~13 cm
²
/Vs for n = 8×10
¹⁹
1/cm
³
to ~120 cm
²
/Vs for n = 1.6×10
¹⁷
1/cm
³
. These values are comparable with the best literature data, despite higher growth rates. For the UID β-Ga
₂
O
₃
layers, Si was identified as the major impurity responsible for the free carrier concentration with strong accumulation at the film/substrate interface. The reactor was also used to grow high quality strained β-(Al
_x
Ga
_1-x
)
₂
O
₃
/β-Ga
₂
O
₃
heterostructures and superlattices with Al content of up to 43%. The results suggest that the MOCVD enables growth of device quality β-Ga
₂
O
₃
and related alloys at a fast growth rate which is critical for high voltage power devices.