Enhanced thickness uniformity of large-scale α-Ga2O3 epilayers grown by vertical hot-wall mist chemical vapor deposition

Rapid epitaxy of 2-inch and high-quality α-Ga2O3 films by mist-CVD method

“…Despite the fact that α-Ga 2 O 3 has a higher formation energy than ε-Ga 2 O 3 and β-Ga 2 O 3 , α-Ga 2 O 3 could be stabilized under the misfit strain created by lattice mismatch. The mismatch strain at the interface is quickly released as the growth temperature rises, leading to the acceleration of ε-Ga 2 O 3 growth [13] .…”

“…where D e (D s ) and b e (b s ) are the dislocation densities and lengths of Burgers vectors for edge (screw) types, respectively. β (0006) and β (10−14) are the FWHM of ω scan for α-Ga 2 O 3 (0006) plane and α-Ga 2 O 3 (10−14) plane [13,25] . The screw and edge dislocation densities in the film prepared at 540 °C were estimated to be 2.3 × 10 6 and 3.9 × 10 10 cm −2 , respectively.…”

“…Additionally, the crystal quality and uniformity of large-scale α-Ga 2 O 3 films were hardly guaranteed with high growth rate [6, 12, 16−20] . Furthermore, other crystalline phases likely appeared in the epitaxy of α-Ga 2 O 3 films [13] . The dominant factors affecting the growth rate are still unclear.…”

A Comprehensive Review on Recent Developments in Ohmic and Schottky Contacts on Ga2O3 for Device Applications

“…To date, dislocation density less than 10 3 cm –2 was achieved in β-Ga 2 O 3 , which is low enough to be suitable for power device applications, while in the α phase, the dislocation density is very high, greater than 10 6 cm –2 , due to large lattice mismatch and large thermal expansion coefficient mismatch that have yet to be reduced. Though fabrication of Schottky barrier diodes (SBDs), field-effect transistors (FETs), and solar-blind photodetectors has been reported with α-Ga 2 O 3 using Ti as ohmic contact and PtO x , AgO x , Ni, and Pt as Schottky contacts, − much more attention has been focused on β-Ga 2 O 3 due to its stability. At present, the only commercial Ga 2 O 3 device is a SBD manufactured by Flosfia, Inc., of Japan using mist chemical vapor deposition (CVD) produced α-Ga 2 O 3 . , In this review, we focus on the literature related to β-Ga 2 O 3 based metal–semiconductor structures.…”

The Effect of Gate Work Function and Electrode Gap on Wide Band-Gap Sn-Doped α-Ga2O3 Metal–Semiconductor Field-Effect Transistors

“…However, it is difficult to produce a β-Ga 2 O 3 wafer with a diameter large enough for practical application due to easy formation of cleavages such that the wafer size is limited to four inches [ 9 ]. Recently, mist chemical vapor deposition (Mist-CVD) has been introduced as a non-vacuum solution-process heteroepitaxy for α-Ga 2 O 3 on mass-produced sapphire (Al 2 O 3 ) wafers up to six inches, with a similar a crystal structure to α-Ga 2 O 3 [ 10 , 11 , 12 , 13 , 14 ]. Being able to lift α-Ga 2 O 3 off of the sapphire substrate and bond it to other substrates with high thermal conductivity (such as SiC, AlN, diamond, etc.)…”